Moscow, Russia – May 22, 2009 – Sistema (LSE: SSA), the largest diversified public financial corporation in Russia and the CIS, which manages large companies operating in different industries, today announced that it has signed supplemental agreements with Agidel-Invest LLC, Ural-Invest LLC, Inzer-Invest LLC and Yuryuzan-Invest LLC to fix in roubles the total acquisition price of a controlling stake in Bashkir Oil and Energy Group, including ANK Bashneft JSC, Ufaneftechim JSC, Novoil JSC, Ufaorgsintez JSC, Ufimskiy NPZ JSC and Bashkirnefteproduct JSC. According to the terms of supplemental agreements, the total price already paid for this transaction is RUB 66.8 billion with no further payments being affected.