Petrobras, Brazil's biggest company, has been at the centre of the country's largest corruption scandal in history
Petrobras, Brazil's biggest company, has been at the centre of the country's largest corruption scandal in historyReuters

Petrobras, which is at the centre of the biggest corporate corruption case in Brazil's history, is aiming to release its much-delayed audited fourth-quarter financial results by the end of March.

The beleaguered Brazilian state oil giant recently released an unaudited version of its third-quarter results after auditor PricewaterhouseCoopers (PwC) refused to sign off on the accounts.

However, in the unaudited accounts, Petrobras failed to report any write-downs associated with an historical corruption scandal that involves kickbacks on contracts with suppliers.

Federal police are investigating allegations that a cartel of construction companies fixed bids on the oil producer's contracts and bribed executives during a span stretching back to when President Dilma Rousseff served as Petrobras' chairman from 2003 to 2010.

Petrobras, as Petroleo Brasileiro is known, has until the end of June to report the results, or it risks facing loan defaults.

By publishing its audited fourth-quarter financial results early, its new chief executive, banker Aldemir Bendine, is hoping to avoid just that.

This comes as Fitch Ratings downgraded Petrobras from BBB to BBB- on 3 February, saying that it had placed all of Petrobras' ratings on negative watch for further downgrades.

The downgraded ratings affect "approximately $50bn of issued debt", Fitch said in a statement, and come amid "increased and prolonged uncertainty" related to Petrobras' financial statements.

Bendine, who took over from Maria das Gracas Foster on Friday (6 February), is now pushing for an end of March date for the release, according to Globo.

Foster, who faces allegations that she ignored corruption warnings from subordinates, was forced to resign on 04 February.

Meanwhile, Rousseff's approval sank to a record low in a poll this week, after voters held her accountable for the escalating corruption investigation.

Tumbling from 42% in December, Rousseff was rated good or very good by 23% of respondents - the lowest level since she took office in 2011.

Most poll respondents said they thought Rousseff was aware of corruption at Petrobras as it was happening.

The president has publicly denied such knowledge.