TotalFinaElf and Rosneft signed an agreement for exploration of the Russian sector of the Black Sea, Rosneft's spokesman said. "This agreement envisages joint research works in the waters close to the city of Tuapse," Alexander Stepanenko said. But declined to give further details. TotalFinaElf signed an agreement in January with YUKOS on exploration of another Black Sea block, Shatsky, which has never been explored. The company is also looking to acquire a 25 percent stake in the Shtokman offshore gas project in the Barents Sea, which is operated by Gazprom and needs $20 billion in investment.