Sir David Murray's metals empire has sold its biggest company, Apollo Metals, to German giant ThyssenKrupp after returning the business to profitability and almost doubling sales.

Murray International Holdings has sold Apollo three years after moving in to buy it in late 2004 as it was emerging from a global slump. Birmingham-based Apollo, a distributor to the international defence and aerospace industries, made a small operating profit in its first full year under Murray after a pre-tax loss of £8.7m the previous year, and lifted sales 8% to £65m.

By the end of 2006 it was said to be well-placed to benefit from "the strong recovery in the global aerospace sector and unprecedented demand for raw material" from customers including Boeing and Airbus, after a turnaround helped by "management reorganisation and significant overhead reductions", according to the group. The expansion included a warehouse and processing presence in China.

Yesterday's announcement said the disposal would cut the turnover of Murray Metals Group (MMG) from £370m to £250m, suggesting that Apollo has almost doubled sales to £120m in the past year.

The price achieved for Apollo is unknown but Graeme Hill, chief executive of MMG, said the sale would offer a "fair return for all stakeholders and one that would enable further expansion of various businesses and markets in which the group operates".

He said the acquisitions of four companies within MMG, following the disposal of the then biggest company in the group, Murray International Metals, in late 2005, was testimony to an ambitious ongoing re-investment strategy.

Apollo was acquired from UK private equity funds a year before the divestment of MIM in a £112m sale to US private equity buyers.

Hill added: "The Murray Metals Group strategy is to build our operations and portfolio of interests and develop each business, with an emphasis on growing value."

The sale will combine Apollo's predominantly European and Far Eastern businesses with Düsseldorf-based Thyssen-Krupp's US-based operations to form a global enterprise in 13 countries with a turnover of more than $700m (£350m).

MMG is a leader in steel and metals stockholding, processing, profiling and distribution. Its businesses include Multi Metals, Premier Alloys, Forth Steel, Northern Steel Stocks, Austin Trumanns Steel, Ireland Alloys, Tipton & Mill, Newton Steel Stock and its most recent acquisition, Parson and Crosland.