Russian President Dmitry Medvedev and Serbian President Boris Tadic signed on 24 December an agreement on cooperation in oil and gas sphere.Owned by Gazprom oil “is moving 51% stake in the largest Serbian oil refining company Naftna Industrija Srbije (NIS). The amount of the transaction to buy a controlling interest amounted to NIS 400 million euros. In addition, the Russian side to further invest in the development of the enterprise until 2012 at least 500 billion euros. Also signed were the main conditions to the basic agreement on the construction of gas pipeline and gas transit through the territory of Serbia, the project Southern flow of Gazprom and Firm Flotation Srbijagas and a memorandum of understanding on cooperation in the field of underground gas storage (UGS Banatski Dvor ) between Gazprom export and Srbijagas. These documents are aimed at implementing the intergovernmental agreement on cooperation in oil and gas industry, concluded on 25 January this year. The total investment on the Russian side agreements with Serbia to reach 1-2,5 billion dollars. Transaction in shares of NIS, is expected to be completed before May 1, 2009. After signing the contract of sale “Gazprom oil” must obtain permission from the Serbian Anti-Monopoly Service, which may consider the application within 130 days. The agreement on South Stream set conditions for the establishment of mechanisms and activities of the JV, which will be formed in the I quarter of 2009 to prepare a justification for investment in the construction of a pipeline in Serbia and its subsequent exploitation. The share of the Russian side in the JV is 51%, Serb – 49%. After signing the agreements, vice-chairman of the Gazprom Alexander Medvedev said that the construction South Flow on the territory of Serbia will be sought from $ 1 billion to more than $ 2.5 billion power station Serb – 10 billion cubic meters. m or more than 20 billion cubic meters. m – will be determined on the preparation of a feasibility study. Medvedev also noted that there are already proven demand for all 31 billion cubic meters. m planned power South Flow .