Petrofac said today that an independent investigation had found no evidence it was involved in a global scandal over bribery and corruption on the oil industry.
The FTSE 250-listed firm called in lawyers and accountants after leaked documents suggested Monaco-based Unaoil paid bribes on behalf of oil companies including Petrofac to win contracts.
"The independent investigation has thoroughly investigated the allegations, based solely on the information available to the company, and recognising the historical nature and wider context beyond Petrofac," the board said in a statement.
"The company confirms that it engaged Unaoil for the provision of local consultancy services primarily in Kazakhstan between 2002 and 2009. The independent investigation did not find evidence confirming the payment of bribes."
"The board considers it appropriate to share the findings of the investigation with the Serious Fraud Office (SFO) and any other relevant authorities, and has noted the SFO's general request for information in relation to its ongoing investigation into the activities of Unaoil."
Petrofac closed up 0.67 per cent to 750.50p per share, having risen as high as 784.50p at the open.
City law firm Freshfields Bruckhaus Deringer and big four accountancy firm KPMG carried out the investigation, which was launched in April.
They were investigating claims that Unaoil made payments for Petrofac to secure contracts in Kazakhstan, Kuwait and Iraq.
The Serious Fraud Office began investigating Unaoil's activities officers, employees and agents in connection with suspected offences of bribery, corruption and money laundering in March.
It came after Australia's Fairfax Media and the Huffington Post reported Unaoil paid bribes on behalf of a number of companies across the world.
Other countries, including Monaco and Iraq, have also opened investigations.