(Adds details and quote from release, context)
By Jeb Blount
RIO DE JANEIRO, Jan 28 (Reuters) - Brazil's Petrobras released unaudited third-quarter results on Wednesday after months of delays, but the state-run oil company left investors in the dark over the financial impact of a multibillion-dollar corruption scandal.
Petroleo Brasileiro SA, as Petrobras is formally known, reported a net profit of 3.09 billion reais ($1.20 billion), down about 9 percent from a year earlier. It had planned to publish the results in November but had to delay the release after a stream of corruption allegations involving the company snowballed into a nationwide scandal.
The much-anticipated results, however, did not include what investors most want to know: a rough estimate of how badly corruption overvalued the company's assets.
Chief Executive Officer Maria das Graças Foster acknowledged that graft and other corruption-related spending had been unduly booked in the past as legitimate costs and thus would have to be revised.
"However, we concluded that it was impractical to quantify these values with precision, given that the payments were made by outside suppliers and cannot be traced to the company's accounting books," Foster wrote in a long letter to shareholders and investors accompanying the earnings release.
According to police, prosecutors and the testimony of individuals indicted in the case, Petrobras executives appointed by politicians conspired with Brazil's largest construction and engineering companies to overcharge for refineries, ships and other goods and services. Some of the excess revenue was then kicked back to executives, politicians and political parties as bribes and campaign contributions.
Police say that graft may have skimmed 3 percent or more off the value of Petrobras projects.
Petrobras said it was looking at ways to account for the losses in accordance with securities regulations in Brazil and the United States.
The results were first delayed after auditor PricewaterhouseCooopers declined to certify Petrobras' accounts due to the allegations. Since then, the company has been under pressure to at least release unaudited results to comply with bond covenants, but it remains to be seen if Wednesday's statement will satisfy debtholders.
Adjusted third-quarter earnings before interest, taxes, depreciation and amortization fell about 10 percent to 11.735 billion reais from a year earlier, the company said.
Petrobras said falling oil prices, which reduce the cost of fuel it imports for the Brazilian market, helped its cash position, giving it "room" to cover operational needs over the course of the year.
"We do not need to make use of new debt in 2015 due to factors favoring our cash flow," Foster said in her letter.
$1 = 2.5721 Brazilian reais Additional reporting by Asher Levine; Editing by Todd Benson and Lisa Von Ahn