ATLANTIC Technology Holdings (UK) in Crumlin has been acquired by a semi-conductor group from the Far East.
Atlantic employs 250 people, and managers hope the deal will bring further investment and jobs.
Unisem (M) Berhad is a listed Malasian group of companies.
It was attracted to Atlantic by its position as one of Europe's best semiconductor assembly and test facilities.
Atlantic has been backed by Finance Wales to the tune of around £1million, and the WDA's venture capital arm is now recouping its money. Finance Wales chief executive Colin Mitten said: "This is the first investment exit for Finance Wales since our inception in 2001.
"The exit has been achieved in a relatively short period since the original investment in Atlantic in April 2002, and has produced an excellent commercial return to the Equity Fund.
"Both the equity funding provided by Finance Wales and the RSA support from the Assembly have been instrumental in moving the company forward in an extremely volatile market."
Economic development and transport minister Andrew Davies said: "The Assembly has been closely involved with Atlantic Technology since its formation.
"Despite the competitive nature of the semi-conductor sector, Atlantic has pursued a successful differentiation strategy.
"The management team and the skilled workforce in Crumlin deserve every credit for that success, and I hope that development will see job numbers continue to grow and the enterprise flourish."
Atlantic was formed in July 1999 as a result of a management buy-out of ASAT (UK), with finance provided by the management team, syndicated venture capitalists and the Bank of Wales.
Substantial capital expenditure created a multi-million-pound assembly and test facility.
The strategy was to grow the Welsh operation while preserving a niche identity with a view to eventually becoming part of a larger international group.
Negotiations have been conducted over the last couple of months and were concluded with a notification to the Malaysian Stock Exchange.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article