Petrofac will plead guilty to seven separate offences of failing to prevent bribery, after a long-running probe by the Serious Fraud Office into payments made in the Middle East.

The company, whose biggest shareholder is a major Tory donor, said it had “indicated guilty pleas” to failing to stop former staff from making payments linked to contracts the business wanted to win.

The payments happened between 2011 and 2017, and since then all the employees have left, Petrofac said.

Following a four-year investigation, the SFO said it had reached a plea agreement with Petrofac, whose representatives appeared at Westminster Magistrates’ Court on Friday.

The case was sent to Southwark Crown Court, where Petrofac will enter its pleas on Monday.

This was a deeply regrettable period of Petrofac's history

Chairman Rene Medori said: “This was a deeply regrettable period of Petrofac’s history.

“We are committed to ensuring it will never happen again.

“We have fundamentally overhauled our compliance regime, as well as the people, and the culture that supports it.

“Our comprehensive programme of corporate renewal has 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.”

The SFO had already secured guilty pleas from David Lufkin, a former executive, surrounding payments totalling 81 million dollars (£60 million at today’s exchange rate) to win contracts worth about 7.5 billion dollars.

The former global head of sales for Petrofac pleaded guilty to eleven counts of bribery in 2019, and a further three counts in 2021.

He is expected to be sentenced on Monday.

Petrofac was formerly run by Ayman Asfari, a Conservative donor who with his wife has given about £800,000 to the party.

Former prime minister David Cameron promoted the company during a two-day stay in Bahrain in 2017, flying back from the country on a plane owned by Mr Asfari, the Guardian reported in 2019.

While serving as prime minister Theresa May wrote to her Bahraini counterpart to support Petrofac’s bid for a contract in the country.

Shares in Petrofac rose about 24% following the news, boosting the value of the 19% of shares owned by Mr Asfari and his family by more than £16 million.