The present invention relates to a method of making of hydrocarbon soluble metal composition comprising of one or more metals of group VIB of the periodic table, wherein the metal having 4+ oxidation state predominantly forms highly active metal sulfide catalyst for hydro-conversion of heavy oil feedstocks in liquid phase. More particularly, present invention relates to a hydrocarbon soluble metal composition comprising of reaction products of a metal source, a lipophilic phenolic acid, a surfactant and an organophosphorus compound. The present invention also provides a one-pot process for preparation of the hydrocarbon soluble metal composition comprising reacting a metal source, a lipophilic phenolic acid, a surfactant, an organophosphorus compound and water to obtain a reaction product and drying the reaction product to obtain the hydrocarbon soluble metal composition.