Russian gas company Gazprom wants Beijing to pay in advance should it shore up a commercial contract with the state energy company, sources said. A source in China\'s National Petroleum Corp. suggested Gazprom wanted $25 billion in advanced payments if it can manage to land a commercial contract with Beijing. \"Gazprom wants an advance payment for gas as soon as a commercial contract has been signed and before (a) gas pipeline has been built,\" the source told the Interfax news agency. \"(CNPC) itself does not have that much cash and it would have to borrow it from a bank and pay the corresponding interest.\" Five years in the making, talks between Gazprom and CNPC hit a road block last month when Chinese President Hu Jintao concluded his state visit to Moscow without a major gas deal in hand. Gazprom officials had said they were focusing on the Asian consumer base. Russian gas monopoly Gazprom announced it signed a deal in April with a Japanese consortium for the possible construction of a liquefied natural gas plant in Russia. Japan is the fourth-largest energy consumer in the world and the top importer of LNG, relying on the resource for 100 percent of its consumed natural gas.