Petrobras delays results as police raid offices Brazilian federal police in six states have raided the offices of Petrobras and several of its contractors in the latest phase of a political corruption case afflicting the state-owned oil company. The raids on Friday, which involved up 300 police officers, came as Petrobras delayed the release of its financial results, and warned that the investigation may force it to "adjust" its accounts. Shares in the company fell 5 per cent in afternoon trading, and are down more than 30 per cent over the past 12 months. "Petrobras is undergoing a unique moment in its history," the company said in a statement. As a result of the time needed to... gain greater understanding from the ongoing investigations... Petrobras is unable to release its third quarter 2014 financial statements at this time. Petrobras, which is noted for its expertise in offshore exploration, is at the centre of a money-laundering investigation in which federal police and prosecutors allege the company was used to pay for an elaborate system of kickbacks. The alleged operators of this system - jailed former Petrobras director Paulo Roberto Costa and black market money dealer Alberto Youssef - have accused the ruling coalition of President Dilma Rousseff of accepting 3 per cent of the value of contracts in the form of kickbacks, from a cartel consisting mostly of major construction companies. The case is sensitive for Ms Rousseff - who narrowly won a second term in office last month - because she led Petrobras before becoming president in 2010. The ruling Workers" Party, or PT, vehemently denies the allegations while the construction companies say they are co-operating with the investigations. On Friday, the federal police said it had arrested 27 people and frozen assets worth R$720m, including those belonging to three companies under investigation. Although the police declined to disclose the names of individuals or companies under investigation, local media reported that they included nine major construction companies that had contracts with Petrobras. Odebrecht, the Brazilian multinational construction group, confirmed on Friday that investigators had visited its office in Rio de Janeiro but said no one was arrested. Rivals Queiro Galvão, Engevix, UTC and Mende Jr did not confirm whether police had attended their premises but said they were co-operating with authorities. Others named in the reports - including Camargo Corrêa and OAS - did not respond to requests for comment. The corruption allegations concerning Petrobras, which is also being probed in the US by the Securities and Exchange Commission and the Department of Justice, threaten to throw the company's books into disarray. Petrobras said on Friday that it would release its third quarter financial results on December 12 but they would not be accompanied by a review by its independent auditors, PwC. The company said it needed more time to allow the private investigators it has hired - Brazilian law firm Trench, Rossi and Watanabe and US law firm Gibson, Dunn and Crutcher - to examine the corruption allegations and their likely impact on the company. Their findings would enable the company to "make any adjustments to the financial statements based on the accusations and investigations" and evaluate its internal controls.