Petrobras and Sinopec have executed a joint venture agreement to explore blocks off the coast of northern Brazil.

Carlos Stenders, Sinopec’s Brazil unit adjunct director, said that the agreements were signed by Brazilian President Dilma Rousseff.

The stakes held by each company were not disclosed.

Both companies signed agreements for the joint development of the BM-PAMA-3 and BM-PAMA-3 blocks won by Petrobras in auctions in 2001 and 2004.