Russian-British joint venture TNK-BP has signed an agreement with Brazil\'s Petro Energia to purchase 45 percent in an oil and gas project in the country\'s Solimoes region, TNK-BP said on Monday. The value of the deal will depend on production of the asset, which includes 21 exploration blocks covering an area of about 48,000 square meters in the Solimoes basin of the Amazon River. The expected reserves of the blocks, owned and operated by Brazil\'s HRT O&G, are estimated at 783 million barrels of oil equivalent under an audit report of Degolyer & MacNaughton. Production at the Solimoes Basin is to be launched in 2012. \"HRT will remain the operator of the Solimoes project, with TNK-BP playing a more active role during the development and production stages,\" TNK-BP said in a statement. \"Negotiations on this project are still ongoing and a number of additional agreements have to be negotiated with the Solimoes operator and majority partner, HRT. Management hopes to have these agreements finalized before the end of August and submit the entire investment for board approval by September,\" TNK-BP Chief Executive Officer Mikhail Fridman was quoted in the statement as saying.