Oil and Gas

UPDATE 1-Exxon Mobil joins Black Sea exploration accord

(Adds details, background)

ISTANBUL, Jan 12 (Reuters) - Exxon Mobil XOM.N is joining a Black Sea exploration agreement with Brazilian energy company Petrobras PETR4.SA and Turkey's state oil firm TPAO, the companies said in a joint statement on Tuesday.

Exxon Mobil and Petrobras will each have a 25 percent stake in the TPAO-Petrobas blocks off the coast of Turkey in the Black Sea, the statement said. TPAO will hold the remaining 50 percent.

The deal, which covers exploration over an area of three million hectares (7.413 million acres) in the Black Sea, will take effect once approved by the Turkish government.

Petrobras said last year it expected investments in the Black Sea totalling $300 million in 2009-2010.

TPAO has said it sees the Black Sea yielding as much as 10 billion barrels of oil and 1.5 trillion cubic metres of natural gas. (Writing by Daren Butler; Editing by Michael Urquhart)