The company indicated its plans at London's Westminster Magistrates' Court after being formally charged by the UK Serious Fraud Office (SFO), drawing a line under a four-year criminal investigation. Its shares surged 25% in relief.

Petrofac, which has struggled to secure key contracts in the Middle East and has seen its shares battered during the SFO investigation, will formally enter its pleas and await sentencing at London's Southwark Crown Court on Monday.

Petrofac said offers or payments to agents to help secure projects were made between 2011 and 2017 but that all employees involved had left.

"This was a deeply regrettable period of Petrofac's history," said Chairman René Medori in a statement, adding that the company's "comprehensive programme of corporate renewal" had been acknowledged by the SFO.

"Petrofac has been living under the shadow of the past, but today it is a profoundly different business, in which stakeholders can be assured of our commitment to the highest standards of business ethics, wherever we operate," he said.

Former executive David Lufkin, who has separately pleaded guilty to 14 charges of bribery to secure billions of dollars worth of contracts for Petrofac in the Middle East, is also expected to be sentenced on Monday.

His lawyer did not immediately respond to a request for comment.

In March, the UAE's state-backed oil firm, ADNOC, barred Petrofac from competing for new contracts in the country.

It is the second corporate guilty plea secured by the SFO in five months.

Former Airbus (AIR.PA)subsidiary GPT Special Project Management pleaded guilty to corruption over military contracts for Saudi Arabia in April.