Brazilian state-owned oil company Petroleo Brasileiro aims to move past a "sad chapter" after taking a massive loss in a graft scandal, its top executive said.

The company known also as Petrobras said in its first audited statement in nearly a year it was writing off around $17 billion, of which $2.1 billion was due to alleged graft.

Aldemir Bendine, the company's top executive, was quoted by The Wall Street Journal as saying during a Wednesday news conference the corruption damage could be even more severe if federal prosecutors find more evidence of graft.

"We were conservative with this number. We might not reach it, but it was a way to give credibility," he said. "We have made our best efforts to turn the page on this sad chapter that the company has passed through."

Oliver Leyland, a fund manager at Mirae Asset Global Investments in New York, told the Journal last year the Brazilian energy company is "pedaling quite hard to stand still." Rogerio Freitas, a manager at Brazil's Teorica Investimentos, said the company is "poorly managed."

Bendine told reporters this week the audited statements were vetted by an independent auditor, noting he stood solidly behind the results.

Corruption scandals have presented a roadblock to reform efforts led by Brazilian President Dilma Rousseff, a former Petrobras chairman. Nicholas Spiro, a managing director at Spiro Sovereign Strategy in London, told Bloomberg News the write-off may be good for business, but bad for the Brazilian political landscape.

"One of the darkest clouds hanging over Brazil is being lifted," he said. "Yet while the company may avert a technical default, the fallout from the scandal has yet to run its course. More importantly, the political damage from the affair is huge."

Petrobras last month said it would try to sell off more than $13 billion in assets.