diff --git a/opm/input/eclipse/EclipseState/Tables/FlatTable.hpp b/opm/input/eclipse/EclipseState/Tables/FlatTable.hpp
index e7846f457..566c74767 100644
--- a/opm/input/eclipse/EclipseState/Tables/FlatTable.hpp
+++ b/opm/input/eclipse/EclipseState/Tables/FlatTable.hpp
@@ -426,6 +426,89 @@ struct WatdentTable : public FlatTable< WATDENTRecord > {
     }
 };
 
+struct SatFuncLETRecord {
+    static constexpr std::size_t size = 17;
+
+    double s1_residual;
+    double s1_critical;
+    double l1_relperm;
+    double e1_relperm;
+    double t1_relperm;
+    double krt1_relperm;
+    double s2_residual;
+    double s2_critical;
+    double l2_relperm;
+    double e2_relperm;
+    double t2_relperm;
+    double krt2_relperm;
+    double l_pc;
+    double e_pc;
+    double t_pc;
+    double pcir_pc;
+    double pct_pc;
+
+    bool operator==(const SatFuncLETRecord& data) const {
+        return s1_residual == data.s1_residual &&
+               s1_critical == data.s1_critical &&
+               l1_relperm == data.l1_relperm &&
+               e1_relperm == data.e1_relperm &&
+               t1_relperm == data.t1_relperm &&
+               krt1_relperm == data.krt1_relperm &&
+               s2_residual == data.s2_residual &&
+               s2_critical == data.s2_critical &&
+               l2_relperm == data.l2_relperm &&
+               e2_relperm == data.e2_relperm &&
+               t2_relperm == data.t2_relperm &&
+               krt2_relperm == data.krt2_relperm &&
+               l_pc == data.l_pc &&
+               e_pc == data.e_pc &&
+               t_pc == data.t_pc &&
+               pcir_pc == data.pcir_pc &&
+               pct_pc == data.pct_pc;
+    }
+
+    template<class Serializer>
+    void serializeOp(Serializer& serializer)
+    {
+        serializer(s1_residual);
+        serializer(s1_critical);
+        serializer(l1_relperm);
+        serializer(e1_relperm);
+        serializer(t1_relperm);
+        serializer(krt1_relperm);
+        serializer(s2_residual);
+        serializer(s2_critical);
+        serializer(l2_relperm);
+        serializer(e2_relperm);
+        serializer(t2_relperm);
+        serializer(krt2_relperm);
+        serializer(l_pc);
+        serializer(e_pc);
+        serializer(t_pc);
+        serializer(pcir_pc);
+        serializer(pct_pc);
+    }
+};
+
+struct SwofletTable : public FlatTable< SatFuncLETRecord > {
+    using FlatTable< SatFuncLETRecord >::FlatTable;
+
+    static SwofletTable serializeObject()
+    {
+        return SwofletTable({{1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0}});
+    }
+};
+
+
+struct SgofletTable : public FlatTable< SatFuncLETRecord > {
+    using FlatTable< SatFuncLETRecord >::FlatTable;
+
+    static SgofletTable serializeObject()
+    {
+        return SgofletTable({{1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0}});
+    }
+};
+
 }
 
 #endif //OPM_FLAT_TABLE_HPP
diff --git a/opm/input/eclipse/EclipseState/Tables/TableManager.hpp b/opm/input/eclipse/EclipseState/Tables/TableManager.hpp
index df3b804b9..87443371e 100644
--- a/opm/input/eclipse/EclipseState/Tables/TableManager.hpp
+++ b/opm/input/eclipse/EclipseState/Tables/TableManager.hpp
@@ -163,6 +163,8 @@ namespace Opm {
         const ShrateTable& getShrateTable() const;
         const Stone1exTable& getStone1exTable() const;
         const WatdentTable& getWatdentTable() const;
+        const SgofletTable& getSgofletTable() const;
+        const SwofletTable& getSwofletTable() const;
         const std::map<int, PlymwinjTable>& getPlymwinjTables() const;
         const std::map<int, SkprwatTable>& getSkprwatTables() const;
         const std::map<int, SkprpolyTable>& getSkprpolyTables() const;
@@ -217,6 +219,8 @@ namespace Opm {
             m_stone1exTable.serializeOp(serializer);
             m_viscrefTable.serializeOp(serializer);
             m_watdentTable.serializeOp(serializer);
+            m_sgofletTable.serializeOp(serializer);
+            m_swofletTable.serializeOp(serializer);
             serializer.vector(m_pvtwsaltTables);
             serializer.vector(m_rwgsaltTables);
             serializer.vector(m_bdensityTables);
@@ -356,6 +360,8 @@ namespace Opm {
         Stone1exTable m_stone1exTable;
         ViscrefTable m_viscrefTable;
         WatdentTable m_watdentTable;
+        SgofletTable m_sgofletTable;
+        SwofletTable m_swofletTable;
         std::vector<PvtwsaltTable> m_pvtwsaltTables;
         std::vector<RwgsaltTable> m_rwgsaltTables;
         std::vector<BrineDensityTable> m_bdensityTables;
diff --git a/src/opm/input/eclipse/EclipseState/Grid/SatfuncPropertyInitializers.cpp b/src/opm/input/eclipse/EclipseState/Grid/SatfuncPropertyInitializers.cpp
index b5e5b19e6..b46360166 100644
--- a/src/opm/input/eclipse/EclipseState/Grid/SatfuncPropertyInitializers.cpp
+++ b/src/opm/input/eclipse/EclipseState/Grid/SatfuncPropertyInitializers.cpp
@@ -93,8 +93,8 @@ namespace {
         }
 
         const auto family1 =       // SGOF/SLGOF and/or SWOF
-            (gas && (tm.hasTables("SGOF") || tm.hasTables("SLGOF"))) ||
-            (wat && tm.hasTables("SWOF"));
+            (gas && ((tm.hasTables("SGOF") || !tm.getSgofletTable().empty()) || tm.hasTables("SLGOF"))) ||
+            (wat && (tm.hasTables("SWOF") || !tm.getSwofletTable().empty()));
         // note: we allow for SOF2 to be part of family1 for threeP + solvent simulations.
 
         const auto family2 =      // SGFN, SOF{2,3}, SWFN
@@ -135,18 +135,27 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& swofTables = tm.getSwofTables();
+        const auto& swofLetTables  = tm.getSwofletTable();
         const auto& swfnTables = tm.getSwfnTables();
 
         const auto famI = [&swofTables]( int i ) {
             return swofTables.getTable<Opm::SwofTable>( i ).getSwColumn().front();
         };
 
+        const auto famI_let = [&swofLetTables]( int i ) {
+            return swofLetTables[i].s1_residual;
+        };
+
         const auto famII = [&swfnTables]( int i ) {
             return swfnTables.getTable<Opm::SwfnTable>( i ).getSwColumn().front();
         };
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
-            case SatfuncFamily::I: return map( famI, Opm::fun::iota( num_tables ) );
+            case SatfuncFamily::I:
+                if( !swofTables.empty() )
+                    return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+                else if ( !swofLetTables.empty() )
+                    return Opm::fun::map( famI_let, Opm::fun::iota( num_tables ) );
             case SatfuncFamily::II: return map( famII, Opm::fun::iota( num_tables ) );
             default:
                 throw std::domain_error("No valid saturation keyword family specified");
@@ -163,18 +172,27 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& swofTables = tm.getSwofTables();
+        const auto& swofLetTables  = tm.getSwofletTable();
         const auto& swfnTables = tm.getSwfnTables();
 
         const auto famI = [&swofTables]( int i ) {
             return swofTables.getTable<Opm::SwofTable>( i ).getSwColumn().back();
         };
 
+        const auto famI_let = [&swofLetTables]( int i ) {
+            return 1.0 - swofLetTables[i].s2_residual;
+        };
+
         const auto famII = [&swfnTables]( int i ) {
             return swfnTables.getTable<Opm::SwfnTable>( i ).getSwColumn().back();
         };
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
-            case SatfuncFamily::I: return map( famI, Opm::fun::iota( num_tables ) );
+            case SatfuncFamily::I:
+                if( !swofTables.empty() )
+                    return map( famI, Opm::fun::iota( num_tables ) );
+                else if ( !swofLetTables.empty() )
+                    return Opm::fun::map( famI_let, Opm::fun::iota( num_tables ) );
             case SatfuncFamily::II: return map( famII, Opm::fun::iota( num_tables ) );
             default:
                 throw std::domain_error("No valid saturation keyword family specified");
@@ -191,6 +209,7 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& sgofTables  = tm.getSgofTables();
+        const auto& sgofLetTables  = tm.getSgofletTable();
         const auto& slgofTables = tm.getSlgofTables();
         const auto& sgfnTables = tm.getSgfnTables();
 
@@ -198,6 +217,10 @@ namespace {
             return sgofTables.getTable<Opm::SgofTable>( i ).getSgColumn().front();
         };
 
+        const auto famI_sgof_let = [&sgofLetTables]( int i ) {
+            return sgofLetTables[i].s1_residual;
+        };
+
         const auto famI_slgof = [&slgofTables]( int i ) {
             return 1.0 - slgofTables.getTable<Opm::SlgofTable>( i ).getSlColumn().back();
         };
@@ -208,11 +231,13 @@ namespace {
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
             case SatfuncFamily::I:
-                if( sgofTables.empty() && slgofTables.empty() )
+                if( sgofTables.empty() && sgofLetTables.empty() && slgofTables.empty() )
                     throw std::runtime_error( "Saturation keyword family I requires either sgof or slgof non-empty" );
 
                 if( !sgofTables.empty() )
                     return Opm::fun::map( famI_sgof, Opm::fun::iota( num_tables ) );
+                else if( !sgofLetTables.empty() )
+                    return Opm::fun::map( famI_sgof_let, Opm::fun::iota( num_tables ) );
                 else
                     return Opm::fun::map( famI_slgof, Opm::fun::iota( num_tables ) );
 
@@ -234,6 +259,8 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& sgofTables  = tm.getSgofTables();
+        const auto& sgofLetTables  = tm.getSgofletTable();
+        const auto& swofLetTables  = tm.getSwofletTable();
         const auto& slgofTables = tm.getSlgofTables();
         const auto& sgfnTables = tm.getSgfnTables();
 
@@ -241,6 +268,11 @@ namespace {
             return sgofTables.getTable<Opm::SgofTable>( i ).getSgColumn().back();
         };
 
+        const auto famI_sgof_let = [&swofLetTables]( int i ) {
+            // Assume this to be 1-swco
+            return 1.0 - swofLetTables[i].s1_residual;
+        };
+
         const auto famI_slgof = [&slgofTables]( int i ) {
             return 1.0 - slgofTables.getTable<Opm::SlgofTable>( i ).getSlColumn().front();
         };
@@ -251,11 +283,13 @@ namespace {
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
             case SatfuncFamily::I:
-                if( sgofTables.empty() && slgofTables.empty() )
+                if( sgofTables.empty() && sgofLetTables.empty() && slgofTables.empty() )
                     throw std::runtime_error( "Saturation keyword family I requires either sgof or slgof non-empty" );
 
                 if( !sgofTables.empty() )
                     return Opm::fun::map( famI_sgof, Opm::fun::iota( num_tables ) );
+                else if( !sgofLetTables.empty() )
+                    return Opm::fun::map( famI_sgof_let, Opm::fun::iota( num_tables ) );
                 else
                     return Opm::fun::map( famI_slgof, Opm::fun::iota( num_tables ) );
 
@@ -335,6 +369,7 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& swofTables = tm.getSwofTables();
+        const auto& swofLetTables  = tm.getSwofletTable();
         const auto& swfnTables = tm.getSwfnTables();
 
         const auto famI = [&swofTables, tolcrit](const int i) -> double
@@ -342,13 +377,21 @@ namespace {
             return critical_water(swofTables.getTable<Opm::SwofTable>(i), tolcrit);
         };
 
+        const auto famI_let = [&swofLetTables]( int i ) {
+            return swofLetTables[i].s1_critical;
+        };
+
         const auto famII = [&swfnTables, tolcrit](const int i) -> double
         {
             return critical_water(swfnTables.getTable<Opm::SwfnTable>(i), tolcrit);
         };
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
-            case SatfuncFamily::I: return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+            case SatfuncFamily::I:
+                if( !swofTables.empty() )
+                    return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+                else if ( !swofLetTables.empty() )
+                    return Opm::fun::map( famI_let, Opm::fun::iota( num_tables ) );
             case SatfuncFamily::II: return Opm::fun::map( famII, Opm::fun::iota( num_tables ) );
             default: throw std::domain_error("No valid saturation keyword family specified");
         }
@@ -396,6 +439,7 @@ namespace {
 
         const auto& sgfnTables = tm.getSgfnTables();
         const auto& sgofTables = tm.getSgofTables();
+        const auto& sgofLetTables  = tm.getSgofletTable();
         const auto& slgofTables = tm.getSlgofTables();
 
         const auto famI_sgof = [&sgofTables, tolcrit](const int i) -> double
@@ -403,6 +447,10 @@ namespace {
             return critical_gas(sgofTables.getTable<Opm::SgofTable>(i), tolcrit);
         };
 
+        const auto famI_sgof_let = [&sgofLetTables]( int i ) {
+            return sgofLetTables[i].s1_critical;
+        };
+
         const auto famI_slgof = [&slgofTables, tolcrit](const int i) -> double
         {
             return critical_gas(slgofTables.getTable<Opm::SlgofTable>(i), tolcrit);
@@ -415,11 +463,13 @@ namespace {
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
             case SatfuncFamily::I:
-                if( sgofTables.empty() && slgofTables.empty() )
+                if( sgofTables.empty() && sgofLetTables.empty() && slgofTables.empty() )
                     throw std::runtime_error( "Saturation keyword family I requires either sgof or slgof non-empty" );
 
                 if( !sgofTables.empty() )
                     return Opm::fun::map( famI_sgof, Opm::fun::iota( num_tables ) );
+                else if( !sgofLetTables.empty() )
+                    return Opm::fun::map( famI_sgof_let, Opm::fun::iota( num_tables ) );
                 else
                     return Opm::fun::map( famI_slgof, Opm::fun::iota( num_tables ) );
 
@@ -486,6 +536,7 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& swofTables = tm.getSwofTables();
+        const auto& swofLetTables  = tm.getSwofletTable();
         const auto& sof2Tables = tm.getSof2Tables();
         const auto& sof3Tables = tm.getSof3Tables();
 
@@ -494,6 +545,10 @@ namespace {
             return critical_oil_water(swofTables.getTable<Opm::SwofTable>(i), tolcrit);
         };
 
+        const auto famI_let = [&swofLetTables]( int i ) {
+            return swofLetTables[i].s2_critical;
+        };
+
         const auto famII_2p = [&sof2Tables, tolcrit](const int i) -> double
         {
             return critical_oil(sof2Tables.getTable<Opm::Sof2Table>(i), tolcrit);
@@ -506,7 +561,11 @@ namespace {
         };
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
-            case SatfuncFamily::I: return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+            case SatfuncFamily::I:
+                if( !swofTables.empty() )
+                    return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+                else if ( !swofLetTables.empty() )
+                    return Opm::fun::map( famI_let, Opm::fun::iota( num_tables ) );
             case SatfuncFamily::II:
                 return ph.active(::Opm::Phase::GAS)
                     ? Opm::fun::map( famII_3p, Opm::fun::iota( num_tables ) )
@@ -559,6 +618,7 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& sgofTables = tm.getSgofTables();
+        const auto& sgofLetTables  = tm.getSgofletTable();
         const auto& slgofTables = tm.getSlgofTables();
         const auto& sof2Tables = tm.getSof2Tables();
         const auto& sof3Tables = tm.getSof3Tables();
@@ -568,6 +628,10 @@ namespace {
             return critical_oil_gas(sgofTables.getTable<Opm::SgofTable>(i), tolcrit) - swco[i];
         };
 
+        const auto famI_sgof_let = [&sgofLetTables]( int i ) {
+            return sgofLetTables[i].s2_critical;
+        };
+
         const auto famI_slgof = [&slgofTables, &swco, tolcrit](const int i) -> double
         {
             return critical_oil_gas(slgofTables.getTable<Opm::SlgofTable>(i), tolcrit) - swco[i];
@@ -586,11 +650,13 @@ namespace {
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
             case SatfuncFamily::I:
-                if( sgofTables.empty() && slgofTables.empty() )
+                if( sgofTables.empty() && sgofLetTables.empty() && slgofTables.empty() )
                     throw std::runtime_error( "Saturation keyword family I requires either sgof or slgof non-empty" );
 
                 if( !sgofTables.empty() )
                     return Opm::fun::map( famI_sgof, Opm::fun::iota( num_tables ) );
+                else if( !sgofLetTables.empty() )
+                    return Opm::fun::map( famI_sgof_let, Opm::fun::iota( num_tables ) );
                 else
                     return Opm::fun::map( famI_slgof, Opm::fun::iota( num_tables ) );
 
@@ -614,6 +680,7 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& sgofTables = tm.getSgofTables();
+        const auto& sgofLetTables  = tm.getSgofletTable();
         const auto& slgofTables = tm.getSlgofTables();
         const auto& sgfnTables = tm.getSgfnTables();
 
@@ -621,6 +688,10 @@ namespace {
             return sgofTables.getTable<Opm::SgofTable>( i ).getKrgColumn().back();
         };
 
+        const auto& famI_sgof_let = [&sgofLetTables]( int i ) {
+            return sgofLetTables[i].krt1_relperm;
+        };
+
         const auto& famI_slgof = [&slgofTables]( int i ) {
             return slgofTables.getTable<Opm::SlgofTable>( i ).getKrgColumn().front();
         };
@@ -631,10 +702,12 @@ namespace {
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
             case SatfuncFamily::I:
-                if( sgofTables.empty() && slgofTables.empty() )
+                if( sgofTables.empty() && sgofLetTables.empty() && slgofTables.empty() )
                     throw std::runtime_error( "Saturation keyword family I requires either sgof or slgof non-empty" );
                 if( !sgofTables.empty() )
                     return Opm::fun::map( famI_sgof, Opm::fun::iota( num_tables ) );
+                else if( !sgofLetTables.empty() )
+                    return Opm::fun::map( famI_sgof_let, Opm::fun::iota( num_tables ) );
                 else
                     return Opm::fun::map( famI_slgof, Opm::fun::iota( num_tables ) );
             case SatfuncFamily::II:
@@ -655,6 +728,7 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& sgofTables = tm.getSgofTables();
+        const auto& sgofLetTables  = tm.getSgofletTable();
         const auto& slgofTables = tm.getSlgofTables();
         const auto& sgfnTables = tm.getSgfnTables();
 
@@ -681,6 +755,11 @@ namespace {
             return sgof.getKrgColumn().eval(ix);
         };
 
+        const auto famI_sgof_let = [&sgofLetTables, &sr](const int i) -> double
+        {
+            return sgofLetTables[i].krt1_relperm;
+        };
+
         const auto famI_slgof = [&slgofTables, &sr](const int i) -> double
         {
             const auto& slgof = slgofTables.getTable<Opm::SlgofTable>(i);
@@ -699,10 +778,12 @@ namespace {
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
             case SatfuncFamily::I:
-                if( sgofTables.empty() && slgofTables.empty() )
+                if( sgofTables.empty() && sgofLetTables.empty() && slgofTables.empty() )
                     throw std::runtime_error( "Saturation keyword family I requires either sgof or slgof non-empty" );
                 if( !sgofTables.empty() )
                     return Opm::fun::map( famI_sgof, Opm::fun::iota( num_tables ) );
+                else if( !sgofLetTables.empty() )
+                    return Opm::fun::map( famI_sgof_let, Opm::fun::iota( num_tables ) );
                 else
                     return Opm::fun::map( famI_slgof, Opm::fun::iota( num_tables ) );
             case SatfuncFamily::II:
@@ -723,6 +804,7 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& swofTables = tm.getSwofTables();
+        const auto& swofLetTables  = tm.getSwofletTable();
         const auto& swfnTables = tm.getSwfnTables();
 
         auto sr = std::vector<double>(num_tables, 0.0);
@@ -748,6 +830,11 @@ namespace {
             return swof.getKrwColumn().eval(ix);
         };
 
+        const auto& famI_let = [&swofLetTables, &sr](const int i) -> double
+        {
+            return swofLetTables[i].krt1_relperm;
+        };
+
         const auto& famII = [&swfnTables, &sr](const int i) -> double
         {
             const auto& swfn = swfnTables.getTable<Opm::SwfnTable>(i);
@@ -758,7 +845,10 @@ namespace {
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
             case SatfuncFamily::I:
-                return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+                if( !swofTables.empty() )
+                    return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+                else if( !swofLetTables.empty() )
+                    return Opm::fun::map( famI_let, Opm::fun::iota( num_tables ) );
             case SatfuncFamily::II:
                 return Opm::fun::map( famII, Opm::fun::iota( num_tables ) );
             default:
@@ -778,6 +868,7 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& swofTables = tm.getSwofTables();
+        const auto& swofLetTables  = tm.getSwofletTable();
         const auto& sof2Tables = tm.getSof2Tables();
         const auto& sof3Tables = tm.getSof3Tables();
 
@@ -790,6 +881,11 @@ namespace {
             return swof.getKrowColumn().eval(ix);
         };
 
+        const auto famI_let = [&swofLetTables, &ep](const int i) -> double
+        {
+            return swofLetTables[i].krt2_relperm;
+        };
+
         const auto famII_3p = [&sof3Tables, &ep](const int i) -> double
         {
             const auto& sof3 = sof3Tables.getTable<Opm::Sof3Table>(i);
@@ -810,7 +906,10 @@ namespace {
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
             case SatfuncFamily::I:
-                return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+                if ( !swofTables.empty() )
+                    return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+                else if ( !swofLetTables.empty() )
+                    return Opm::fun::map( famI_let, Opm::fun::iota( num_tables ) );
             case SatfuncFamily::II:
                 return ph.active(::Opm::Phase::GAS)
                     ? Opm::fun::map( famII_3p, Opm::fun::iota( num_tables ) )
@@ -832,6 +931,7 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& sgofTables = tm.getSgofTables();
+        const auto& sgofLetTables = tm.getSgofletTable();
         const auto& slgofTables = tm.getSlgofTables();
         const auto& sof2Tables = tm.getSof2Tables();
         const auto& sof3Tables = tm.getSof3Tables();
@@ -845,6 +945,11 @@ namespace {
             return sgof.getKrogColumn().eval(ix);
         };
 
+        const auto famI_sgof_let = [&sgofLetTables, &ep](const int i) -> double
+        {
+            return sgofLetTables[i].krt2_relperm;
+        };
+
         const auto famI_slgof = [&slgofTables, &ep](const int i) -> double
         {
             const auto& slgof = slgofTables.getTable<Opm::SlgofTable>(i);
@@ -873,10 +978,12 @@ namespace {
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
             case SatfuncFamily::I:
-                if( sgofTables.empty() && slgofTables.empty() )
+                if( sgofTables.empty() && sgofLetTables.empty() && slgofTables.empty() )
                     throw std::runtime_error( "Saturation keyword family I requires either sgof or slgof non-empty" );
                 if( !sgofTables.empty() )
                     return Opm::fun::map( famI_sgof, Opm::fun::iota( num_tables ) );
+                else if( !sgofLetTables.empty() )
+                    return Opm::fun::map( famI_sgof_let, Opm::fun::iota( num_tables ) );
                 else
                     return Opm::fun::map( famI_slgof, Opm::fun::iota( num_tables ) );
             case SatfuncFamily::II:
@@ -908,6 +1015,7 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& sgofTables = tm.getSgofTables();
+        const auto& sgofLetTables = tm.getSgofletTable();
         const auto& slgofTables = tm.getSlgofTables();
         const auto& sgfnTables = tm.getSgfnTables();
 
@@ -915,6 +1023,10 @@ namespace {
             return sgofTables.getTable<Opm::SgofTable>( i ).getPcogColumn().back();
         };
 
+        const auto& famI_sgof_let = [&sgofLetTables]( int i ) {
+            return sgofLetTables[i].pct_pc;
+        };
+
         const auto& famI_slgof = [&slgofTables]( int i ) {
             return slgofTables.getTable<Opm::SlgofTable>( i ).getPcogColumn().front();
         };
@@ -925,10 +1037,12 @@ namespace {
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
             case SatfuncFamily::I:
-                if( sgofTables.empty() && slgofTables.empty() )
+                if( sgofTables.empty() && sgofLetTables.empty() && slgofTables.empty() )
                     throw std::runtime_error( "Saturation keyword family I requires either sgof or slgof non-empty" );
                 if( !sgofTables.empty() )
                     return Opm::fun::map( famI_sgof, Opm::fun::iota( num_tables ) );
+                else if( !sgofLetTables.empty() )
+                    return Opm::fun::map( famI_sgof_let, Opm::fun::iota( num_tables ) );
                 else
                     return Opm::fun::map( famI_slgof, Opm::fun::iota( num_tables ) );
             case SatfuncFamily::II:
@@ -949,19 +1063,27 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& swofTables = tm.getSwofTables();
+        const auto& swofLetTables = tm.getSwofletTable();
         const auto& swfnTables = tm.getSwfnTables();
 
         const auto& famI = [&swofTables]( int i ) {
             return swofTables.getTable<Opm::SwofTable>( i ).getPcowColumn().front();
         };
 
+        const auto& famI_let = [&swofLetTables]( int i ) {
+            return swofLetTables[i].pct_pc;
+        };
+
         const auto& famII = [&swfnTables]( int i ) {
             return swfnTables.getTable<Opm::SwfnTable>( i ).getPcowColumn().front();
         };
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
             case SatfuncFamily::I:
-                return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+                if (!swofTables.empty())
+                    return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+                else if (!swofLetTables.empty())
+                    return Opm::fun::map( famI_let, Opm::fun::iota( num_tables ) );
             case SatfuncFamily::II:
                 return Opm::fun::map( famII, Opm::fun::iota( num_tables ) );
             default:
@@ -981,6 +1103,8 @@ namespace {
         const auto wat = ph.active(::Opm::Phase::WATER);
 
         const auto& other_f1   = wat ? tm.getSwofTables() : tm.getSgofTables();
+        const auto& wat_f1_let   = tm.getSwofletTable();
+        const auto& gas_f1_let   = tm.getSgofletTable();
         const auto& sof2Tables = tm.getSof2Tables();
         const auto& sof3Tables = tm.getSof3Tables();
 
@@ -993,6 +1117,18 @@ namespace {
                 : other_f1.getTable<Opm::SgofTable>( i ).getKrogColumn().front();
         };
 
+        const auto& famI_let_wat = [&wat_f1_let]( int i ) {
+            // In O/W/G runs this relies on Krog(Sg=0) == Krow(Sw=Swco),
+            // meaning that in each region krt2_relperm is equal for SGOFLET and SWOFLET.
+            return wat_f1_let[i].krt2_relperm;
+        };
+
+        const auto& famI_let_gas = [&gas_f1_let]( int i ) {
+            // In O/W/G runs this relies on Krog(Sg=0) == Krow(Sw=Swco),
+            // meaning that in each region krt2_relperm is equal for SGOFLET and SWOFLET.
+            return gas_f1_let[i].krt2_relperm;
+        };
+
         const auto& famII_2p = [&sof2Tables]( int i ) {
             return sof2Tables.getTable<Opm::Sof2Table>( i ).getKroColumn().back();
         };
@@ -1003,7 +1139,12 @@ namespace {
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
             case SatfuncFamily::I:
-                return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+                if ( !other_f1.empty() )
+                    return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+                else if ( !wat_f1_let.empty() )
+                    return Opm::fun::map( famI_let_wat, Opm::fun::iota( num_tables ) );
+                else if ( !gas_f1_let.empty() )
+                    return Opm::fun::map( famI_let_gas, Opm::fun::iota( num_tables ) );
             case SatfuncFamily::II:
                 return ph.active(::Opm::Phase::GAS) && ph.active(::Opm::Phase::WATER)
                     ? Opm::fun::map( famII_3p, Opm::fun::iota( num_tables ) )
@@ -1023,19 +1164,28 @@ namespace {
             return std::vector<double>(num_tables, 0.0);
 
         const auto& swofTables = tm.getSwofTables();
+        const auto& swofLetTables  = tm.getSwofletTable();
         const auto& swfnTables = tm.getSwfnTables();
 
         const auto& famI = [&swofTables]( int i ) {
             return swofTables.getTable<Opm::SwofTable>( i ).getKrwColumn().back();
         };
 
+        const auto& famI_let = [&swofLetTables]( int i ) {
+            return swofLetTables[i].krt1_relperm;
+        };
+
         const auto& famII = [&swfnTables]( int i ) {
             return swfnTables.getTable<Opm::SwfnTable>( i ).getKrwColumn().back();
         };
 
         switch( getSaturationFunctionFamily( tm, ph ) ) {
             case SatfuncFamily::I:
-                return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+                if( !swofTables.empty() )
+                    return Opm::fun::map( famI, Opm::fun::iota( num_tables ) );
+                else if( !swofLetTables.empty() )
+                    return Opm::fun::map( famI_let, Opm::fun::iota( num_tables ) );
+
             case SatfuncFamily::II:
                 return Opm::fun::map( famII, Opm::fun::iota( num_tables ) );
             default:
diff --git a/src/opm/input/eclipse/EclipseState/Runspec.cpp b/src/opm/input/eclipse/EclipseState/Runspec.cpp
index ed94d5916..2dc4a22e3 100644
--- a/src/opm/input/eclipse/EclipseState/Runspec.cpp
+++ b/src/opm/input/eclipse/EclipseState/Runspec.cpp
@@ -88,7 +88,8 @@ namespace {
         const auto family1 =       // SGOF/SLGOF and/or SWOF
             (gas && (deck.hasKeyword<Opm::ParserKeywords::SGOF>() ||
                      deck.hasKeyword<Opm::ParserKeywords::SLGOF>())) ||
-            (wat && deck.hasKeyword<Opm::ParserKeywords::SWOF>());
+            (wat && deck.hasKeyword<Opm::ParserKeywords::SWOF>()) ||
+            (wat && deck.hasKeyword<Opm::ParserKeywords::SWOFLET>());
 
         // note: we allow for SOF2 to be part of family1 for threeP +
         // solvent simulations.
diff --git a/src/opm/input/eclipse/EclipseState/Tables/TableManager.cpp b/src/opm/input/eclipse/EclipseState/Tables/TableManager.cpp
index 59e93ab00..10131a7a5 100644
--- a/src/opm/input/eclipse/EclipseState/Tables/TableManager.cpp
+++ b/src/opm/input/eclipse/EclipseState/Tables/TableManager.cpp
@@ -211,6 +211,12 @@ DensityTable make_density_table(const GravityTable& gravity) {
         if( deck.hasKeyword( "WATDENT" ) )
             this->m_watdentTable = WatdentTable( deck["WATDENT"].back() );
 
+        if( deck.hasKeyword( "SGOFLET" ) )
+            this->m_sgofletTable = SgofletTable( deck["SGOFLET"].back() );
+
+        if( deck.hasKeyword( "SWOFLET" ) )
+            this->m_swofletTable = SwofletTable( deck["SWOFLET"].back() );
+
         if( deck.hasKeyword( "RTEMP" ) )
             m_rtemp = deck["RTEMP"].back().getRecord(0).getItem("TEMP").getSIDouble( 0 );
         else if (deck.hasKeyword( "RTEMPA" ) )
@@ -297,6 +303,8 @@ DensityTable make_density_table(const GravityTable& gravity) {
         result.m_stone1exTable = Stone1exTable::serializeObject();
         result.m_viscrefTable = ViscrefTable::serializeObject();
         result.m_watdentTable = WatdentTable::serializeObject();
+        result.m_sgofletTable = SgofletTable::serializeObject();
+        result.m_swofletTable = SwofletTable::serializeObject();
         result.m_pvtwsaltTables = {PvtwsaltTable::serializeObject()};
         result.m_rwgsaltTables = {RwgsaltTable::serializeObject()};
         result.m_bdensityTables = {BrineDensityTable::serializeObject()};
@@ -1117,6 +1125,14 @@ DensityTable make_density_table(const GravityTable& gravity) {
         return this->m_watdentTable;
     }
 
+    const SgofletTable& TableManager::getSgofletTable() const {
+        return this->m_sgofletTable;
+    }
+
+    const SwofletTable& TableManager::getSwofletTable() const {
+        return this->m_swofletTable;
+    }
+
     const TableContainer& TableManager::getMsfnTables() const {
         return getTables("MSFN");
     }
@@ -1241,6 +1257,8 @@ DensityTable make_density_table(const GravityTable& gravity) {
                m_stone1exTable == data.m_stone1exTable &&
                m_viscrefTable == data.m_viscrefTable &&
                m_watdentTable == data.m_watdentTable &&
+               m_sgofletTable == data.m_sgofletTable &&
+               m_swofletTable == data.m_swofletTable &&
                m_pvtwsaltTables == data.m_pvtwsaltTables &&
                m_rwgsaltTables == data.m_rwgsaltTables &&
                m_bdensityTables == data.m_bdensityTables &&
diff --git a/src/opm/input/eclipse/EclipseState/Tables/Tables.cpp b/src/opm/input/eclipse/EclipseState/Tables/Tables.cpp
index 4302cbe72..b3a862def 100644
--- a/src/opm/input/eclipse/EclipseState/Tables/Tables.cpp
+++ b/src/opm/input/eclipse/EclipseState/Tables/Tables.cpp
@@ -1551,5 +1551,6 @@ template FlatTable< ShrateRecord >::FlatTable( const DeckKeyword& );
 template FlatTable< Stone1exRecord >::FlatTable( const DeckKeyword& );
 template FlatTable< TlmixparRecord>::FlatTable( const DeckKeyword& );
 template FlatTable< WATDENTRecord >::FlatTable( const DeckKeyword& );
+template FlatTable< SatFuncLETRecord >::FlatTable( const DeckKeyword& );
 
 } // namespace Opm
diff --git a/src/opm/input/eclipse/share/keywords/keyword_list.cmake b/src/opm/input/eclipse/share/keywords/keyword_list.cmake
index ff304d0e3..ba84fb1dd 100644
--- a/src/opm/input/eclipse/share/keywords/keyword_list.cmake
+++ b/src/opm/input/eclipse/share/keywords/keyword_list.cmake
@@ -1119,6 +1119,7 @@ set( keywords
      900_OPM/S/SALTSOL
      900_OPM/S/SBIOF
      900_OPM/S/SCALC
+     900_OPM/S/SGOFLET
      900_OPM/S/SKPRPOLY
      900_OPM/S/SKPRWAT
      900_OPM/S/SMICR
@@ -1126,6 +1127,7 @@ set( keywords
      900_OPM/S/SPIDER
      900_OPM/S/SPOLYMW
      900_OPM/S/SUREA
+     900_OPM/S/SWOFLET
      900_OPM/T/TLPMIXPA
      900_OPM/V/VAPWAT
      900_OPM/W/WMICP
diff --git a/src/opm/parser/eclipse/share/keywords/900_OPM/S/SGOFLET b/src/opm/parser/eclipse/share/keywords/900_OPM/S/SGOFLET
new file mode 100644
index 000000000..9b0824031
--- /dev/null
+++ b/src/opm/parser/eclipse/share/keywords/900_OPM/S/SGOFLET
@@ -0,0 +1,115 @@
+{
+  "name": "SGOFLET",
+  "sections": [
+    "PROPS"
+  ],
+  "size": {
+    "keyword": "TABDIMS",
+    "item": "NTSFUN"
+  },
+  "requires": ["GAS", "OIL"],
+  "items": [
+    {
+      "name": "SG_0",
+      "value_type": "DOUBLE",
+      "default": 0,
+      "dimension": "1"
+    },
+    {
+      "name": "SG_CRITICAL",
+      "value_type": "DOUBLE",
+      "default": 0,
+      "dimension": "1"
+    },
+    {
+      "name": "L_GAS",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "E_GAS",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "T_GAS",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "KRT_GAS",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "SO_0",
+      "value_type": "DOUBLE",
+      "default": 0,
+      "dimension": "1"
+    },
+    {
+      "name": "SO_CRITICAL",
+      "value_type": "DOUBLE",
+      "default": 0,
+      "dimension": "1"
+    },
+    {
+      "name": "L_OIL",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "E_OIL",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "T_OIL",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "KRT_OIL",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "L_PC",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "E_PC",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "T_PC",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "PCIR",
+      "value_type": "DOUBLE",
+      "default": 0,
+      "dimension": "Pressure"
+    },
+    {
+      "name": "PCT",
+      "value_type": "DOUBLE",
+      "default": 0,
+      "dimension": "Pressure"
+    }
+  ]
+}
diff --git a/src/opm/parser/eclipse/share/keywords/900_OPM/S/SWOFLET b/src/opm/parser/eclipse/share/keywords/900_OPM/S/SWOFLET
new file mode 100644
index 000000000..bb34b9af8
--- /dev/null
+++ b/src/opm/parser/eclipse/share/keywords/900_OPM/S/SWOFLET
@@ -0,0 +1,115 @@
+{
+  "name": "SWOFLET",
+  "sections": [
+    "PROPS"
+  ],
+  "size": {
+    "keyword": "TABDIMS",
+    "item": "NTSFUN"
+  },
+  "requires": ["OIL", "WATER"],
+  "items": [
+    {
+      "name": "SW_RESIDUAL",
+      "value_type": "DOUBLE",
+      "default": 0,
+      "dimension": "1"
+    },
+    {
+      "name": "SW_CRITICAL",
+      "value_type": "DOUBLE",
+      "default": 0,
+      "dimension": "1"
+    },
+    {
+      "name": "L_WATER",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "E_WATER",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "T_WATER",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "KRT_WATER",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "SO_RESIDUAL",
+      "value_type": "DOUBLE",
+      "default": 0,
+      "dimension": "1"
+    },
+    {
+      "name": "SO_CRITICAL",
+      "value_type": "DOUBLE",
+      "default": 0,
+      "dimension": "1"
+    },
+    {
+      "name": "L_OIL",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "E_OIL",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "T_OIL",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "KRT_OIL",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "L_PC",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "E_PC",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "T_PC",
+      "value_type": "DOUBLE",
+      "default": 1,
+      "dimension": "1"
+    },
+    {
+      "name": "PCIR",
+      "value_type": "DOUBLE",
+      "default": 0,
+      "dimension": "Pressure"
+    },
+    {
+      "name": "PCT",
+      "value_type": "DOUBLE",
+      "default": 0,
+      "dimension": "Pressure"
+    }
+  ]
+}