Brazilian state-controlled energy giant Petrobras said Friday it sold a 12 percent stake in an oil block off Tanzania's coast to Norway's Statoil.

The transaction, whose value was not disclosed, is part of a $9.9 billion divestment program Petrobras announced earlier this year.

Petrobras will remain the operator of Block 6, a 5,549-sq. kilometer (2,140-sq.-mile) area in the Mafia offshore basin, with a 38 percent stake.

Royal Dutch Shell's 50 percent stake is now the largest in the block and Statoil will have the remaining 12 percent, although the deal is still subject to approval by Tanzanian authorities.

Petrobras' divestment strategy is aimed at funding a portion of the company's $236.7 billion investment plan for the 2013-17 period.

The majority of the funds are to be spent on exploration and production, including in ultra-deep fields in the highly promising pre-salt layer.

Petrobras sold off stakes in exploration blocks in the U.S. Gulf of Mexico in April as part of the divestment plan, and since last year has been negotiating the potential sale of different assets in Argentina. EFE