A catalyst composition, comprising: a metal-incorporated support material that is loaded with an active metal precursor, the metal-incorporated support material being impregnated with a hydrocarbon oil, and a polar additive having a boiling point in the range of from 60 °C to 275 °C, wherein the weight ratio of said hydrocarbon oil to polar additive is in the range of from 0.01:1 to 10:1 and wherein at least 75 % of the pore volume of the metal-incorporated support material is filled with the hydrocarbon oil and polar additive; wherein said support material comprises inorganic oxide materials selected from alumina, silica, silica-alumina, magnesia, zirconia, boria, titania and mixtures of any two or more of such inorganic oxides; and wherein said active metal precursor is a metal compound that includes: (i) a Group 9 and Group 10 metal component selected from the group consisting of cobalt and nickel, and wherein said Group 9 and Group 10 metal component is present in said composition in an amount in the range of from 0.5 wt.% to 20 wt.% based on the dry support material and the metal component regardless of the actual form of the metal component; and (ii) a Group 6 metal component, wherein said Group 6 metal component is molybdenum, and wherein said Group 6 metal component is present in said composition in an amount in the range of from 5 wt.% to 50 wt.% based on the dry support material and the metal component regardless of the actual form of the metal component; and (iii) phosphorous; wherein said hydrocarbon oil consists of hydrocarbons having a boiling temperature in the range of from 100 °C to 550 °C and can be selected from hydrocarbon mixtures of the group consisting of heavy naphtha, kerosene, diesel, gas oil, olefins having carbon numbers in the range of from 12 to 40 carbons, mixtures of alpha olefins having carbon numbers in the range of from 18 to 30; and wherein said polar additive is a heterocompound, excluding sulfur-containing compounds and excluding paraffin and olefin hydrocarbon compounds, and selected from the group consisting of tetramethylurea, N-methylpyrrolidone, and dimethylformamide; wherein the metal-incorporated support material is impregnated with the hydrocarbon oil and the polar additive before it is treated with hydrogen followed by treatment with a sulfur compound; characterised in that the metal-incorporated support material is uncalcined and non-sulfided when it is impregnated with the hydrocarbon oil and the polar additive. a metal-incorporated support material that is loaded with an active metal precursor, the metal-incorporated support material being impregnated with a hydrocarbon oil, and a polar additive having a boiling point in the range of from 60 °C to 275 °C, wherein the weight ratio of said hydrocarbon oil to polar additive is in the range of from 0.01:1 to 10:1 and wherein at least 75 % of the pore volume of the metal-incorporated support material is filled with the hydrocarbon oil and polar additive; wherein said support material comprises inorganic oxide materials selected from alumina, silica, silica-alumina, magnesia, zirconia, boria, titania and mixtures of any two or more of such inorganic oxides; and wherein said active metal precursor is a metal compound that includes: (i) a Group 9 and Group 10 metal component selected from the group consisting of cobalt and nickel, and wherein said Group 9 and Group 10 metal component is present in said composition in an amount in the range of from 0.5 wt.% to 20 wt.% based on the dry support material and the metal component regardless of the actual form of the metal component; and (ii) a Group 6 metal component, wherein said Group 6 metal component is molybdenum, and wherein said Group 6 metal component is present in said composition in an amount in the range of from 5 wt.% to 50 wt.% based on the dry support material and the metal component regardless of the actual form of the metal component; and (iii) phosphorous; (i) a Group 9 and Group 10 metal component selected from the group consisting of cobalt and nickel, and wherein said Group 9 and Group 10 metal component is present in said composition in an amount in the range of from 0.5 wt.% to 20 wt.% based on the dry support material and the metal component regardless of the actual form of the metal component; and (ii) a Group 6 metal component, wherein said Group 6 metal component is molybdenum, and wherein said Group 6 metal component is present in said composition in an amount in the range of from 5 wt.% to 50 wt.% based on the dry support material and the metal component regardless of the actual form of the metal component; and (iii) phosphorous; wherein said hydrocarbon oil consists of hydrocarbons having a boiling temperature in the range of from 100 °C to 550 °C and can be selected from hydrocarbon mixtures of the group consisting of heavy naphtha, kerosene, diesel, gas oil, olefins having carbon numbers in the range of from 12 to 40 carbons, mixtures of alpha olefins having carbon numbers in the range of from 18 to 30; and wherein said polar additive is a heterocompound, excluding sulfur-containing compounds and excluding paraffin and olefin hydrocarbon compounds, and selected from the group consisting of tetramethylurea, N-methylpyrrolidone, and dimethylformamide; wherein the metal-incorporated support material is impregnated with the hydrocarbon oil and the polar additive before it is treated with hydrogen followed by treatment with a sulfur compound; characterised in that the metal-incorporated support material is uncalcined and non-sulfided when it is impregnated with the hydrocarbon oil and the polar additive.