An oil production ship sailed from Rio de Janeiro on route for a Brazilian offshore oil field owned by Brazil's state-run Petrobras, Britain's BG Group Plc, and a joint venture between Spain's Repsol SA and China's Sinopec, Petrobras said on Wednesday.

The ship, known as the Cidade de Ilhabela, is expected to begin operations by the end of the year in the Sapinhoa offshore field in the BM-S-9 block south of Rio. More than a year behind schedule, Petroleo Brasileiro SA, as Petrobras is formally known, is counting on the vessel to help boost production and revenue after five years of stagnating output.

The floating production, storage and offloading ship, or FPSO, is being leased from the Netherlands's SBM Offshore NV , and Brazil's Queiroz Galvao Oil and Gas, Petrobras said in a statement.

The ship sails as the future of SBM in Brazil is in doubt. The company, the world's largest operator of FPSOs is under investigation in several countries after allegations from a former employee emerged in February suggesting SBM paid $250 million in bribes, with $139 million of that paid in Brazil.

The company's right to bid for future FPSO leasing contracts was suspended until it can answer questions from Petrobras, the Brazilian oil company said last week. SBM said on Sept. 11 that it expects to be able to bid for contracts again after Brazilian elections in October, and that a Petrobras investigation found no wrongdoing.

The FPSO Cidade de Ilhabela has the a capacity to produce 150,000 barrels of oil and 6 million cubic meters of gas a day.

The Sapinhoa field in Brazil's BM-S-9 block is 45 percent owned by Petrobras, 30 percent owned by BG, and 25 percent by Repsol-Sinopec.