The Herald revealed in June that Sir David Murray and his long-standing lieutenant Donald Wilson were in discussions about a sale of Premier Hytemp, cited this year by Scottish Enterprise as a flagship for international growth.
Mr Wilson, who stepped down from the MIH board in March to become managing director of its oil and gas division, is thought to have done so in order to work on a buyout of Premier, whittling down the MIH empire still further. Its last accounts showed £470m of debt to Lloyds Banking Group, after a £268m capital injection by the bank since 2010.
This year it has already separated the Murray Capital business and confirmation of the wider steels disposal is expected in the near future.
Mr Wilson, 49, is an accountant who has worked for Sir David since the 1990s and is the former chief executive of MIH. He was a director of Rangers between 2000 and October 2009.
Premier Hytemp, based at Newbridge near Edinburgh, reported a £1.6m loss in the year to June 2011, on turnover up by one-third to £52m, but sources close to MIH said that in the year to June 2012 it will post earnings before interest, tax, depreciation and amortisation of around £4m. The deal, however, does not include the Ireland Alloys business, leaving Premier with turnover of £42m.
Dunedin, the Edinburgh-based buyout specialist, said Premier was a global leader in the manufacture and supply chain management of quality engineered alloy components for the offshore and onshore oil and gas industry.
It has manufacturing facilities in Edinburgh, Sheffield and Singapore, operations in Calgary, Canada, and is shortly to open a base in Dubai.
Premier Hytemp was formed in 2008 when Sir David's Premier Alloys, established in 1985, acquired Sheffield-based Hillfoot Steel which owned oil specialist Hytemp, set up in 1976.
Dunedin said the business had "a very strong heritage of engineering excellence".
Dougal Bennett, Dunedin partner who led the deal and now joins the board, said: "Premier Hytemp fits with Dunedin's strategy of investing in UK headquartered companies that are market leaders in their niche and which have strong international growth prospects.
"Commercially, Premier Hytemp is one of a few companies within its sector that has the requisite engineering skills, customer approvals, certifications and geographical reach to meet the increasingly demanding needs of this industry."
He said the business had "fantastic opportunities for growth overseas and domestically".
Mr Wilson said the company wants to further develop the Middle Eastern, North American and South American markets and to maintain investment. "This will enable us to improve support of our key customers as they continue to grow on a global scale," he said.
The management team includes Will Gold, chief financial officer, and Doug Harrison, chief operations officer.
Mike McGill, group finance director of MIH, said: "The transaction reflects Murray International Holdings' continued focus on business turnaround, asset realisation and debt reduction from across its wide portfolio."