Five Scottish entrepreneurs are to share a windfall worth more than £25m after their company was acquired by US oil services giant Halliburton, marking a lucrative finale to their involvement in a business they rescued four years ago from the brink of collapse.

Douglas Duguid led a £14m management buy-out of PSL Energy Services, which is based in Portlethen, just south of Aberdeen, in 2003 after securing equity backing from Connecticut-based private equity investor Lime Rock Partners and debt financing from the Bank of Scotland.

No sale price was disclosed yesterday, although an insider said it was "well in excess of £125m" but less than the "£200m mark". Another described the transaction as "very large in terms of Scottish oil industry deals".

PSL is a major provider of pipeline and well services, with operations in Stavanger, Great Yarmouth, Houston, Singapore, Abu Dhabi, Doha, Baku and Algeria.

Asked if he was pleased with the sale, Turriff-born Duguid attempted to downplay the success of the moment yesterday.

"It's been a hard day of talks," he said, without enthusiasm. "I won't say I'm sad to sell the company, but there has definitely been a bit of a connection over the years of building it up the way we have."

Halliburton, which was run by Dick Cheney - now the US vice-president - until he joined the race for the White House in 2000, said the agreement remains subject to regulatory approval, which is expected to take no more than 60 days.

The Duguid-led MBO four years ago snatched the stricken operation from the jaws of receivership and saved more than 200 jobs. PSL had been forced into receivership in 2003 because it was incapable of servicing debts of more than £36m.

The MBO also laid the foundations for a radical restructuring of the business and a return to profitability and growth.

The company, fuelled by the success of an international growth strategy, now employs more than 1100 workers, 525 of them at the Aberdeen headquarters, and in 2006 reported a surge in pre-tax profits to £8.5m on a £96m turnover.

An insider said Halliburton had acquired the company primarily for its proprietary technologies and that no redundancies were planned.

Under the original MBO's financial structure, Lime Rock Partners owns 80% of the equity in PSL and will walk away with at least £100m, a respectable return on an investment approximately £11.2m less than four years ago.

Duguid, the company's managing director who is also the largest shareholder among the MBO team, will share £25m with Michael Buchan, PSL's finance director, operations director Phil Bentley, Derek Grant, the commercial director, and business development director John Wingfield.

Their windfall is also a healthy return of an initial investment of around £3.8m in 2003. Under the terms of the deal, all five remain with the company until the end of the year.

Asked about what he plans to do with money, Duguid said: "I won't be spending my time on the beach in the Bahamas. Anyone who knows me knows that I love my work.

"I have a few business ideas I'd like to pursue, all still in the oil sector, but it's too early to give details."

Halliburton, which is the US military's biggest logistics contractor in Iraq and which announced in March it would split its corporate headquarters between Houston, Texas, and Dubai, yesterday made its own statement to the New York Stock Exchange, where it is listed. "Geographic growth in the eastern hemisphere and expanded proprietary service technologies are compelling reasons for this acquisition," said David King, senior vice-president of Halliburton's production optimisation division. "Bringing the two companies together will greatly improve our ability to help our customers meet their goals for production enhancement."