Petrobras CEO, 5 executives step down after corruption inquiry

Embattled Brazilian oil giant Petrobras says the company's CEO Graca Foster and five executive directors have stepped down.

The corruption-wracked firm said in a one-line statement that the board will elect new executive members on Friday.

Petrobras has been mired for months in a corruption case involving several top company officials as well as the heads of many of Brazil's main construction companies. The scandal is widely seen as among the biggest in Brazilian history.

Speculation has been rife that Foster would be sacked, but her friend and ally Brazilian President Dilma Rousseff had been seen as defending her.

Rousseff, herself a former chair of Petrobras, has been accused of being involved and there have been calls for her resignation, though she denied all wrongdoing.

Wednesday's brief announcement comes a day after rumours of Foster's departure sent Petrobras shares soaring by 16 per cent.The shares jumped a further eight per cent on Wednesday on confirmation of the resignations.

Three dozen executives at Petrobras and many of its suppliers have testified in an inquiry that alleges kickbacks, price-fixing and bribes at the oil company.

Three former Petrobras executives may face charges in the case, which prosecutors said uncovered $800 million in bribes and illegal funds.