Unions raised the threat of job cuts today after one of Sussex's biggest manufacturing companies was sold to a private equity firm for £460 million.

The Linde Group has agreed to sell vacuum pump maker BOC Edwards, which employs 1,350 people in Sussex, to the US investment vehicle CCMP Capital.

BOC Edwards, which also makes semiconducters, is based in Manor Royal, Crawley, and has sites in Dolphin Road, Shoreham, Albert Drive, Burgess Hill, and Marshall Road, Eastbourne.

The deal comes six months after Linde paid £8.2 billion for BOC Group. At the time, German-based Linde said it intended to focus on its global gases operations and would review options for the "strategic divestment" of BOC Edwards.

Private equity firms, which use large-scale borrowing to carry out company buy-outs, have been under increased scrutiny after taking on well-known names such as the AA, Birds Eye and MFI.

Unions have accused them of asset-stripping and blamed them for widespread job losses.

Paul Maloney, from the GMB Union, said: "If I was a worker at BOC Edwards I would be looking over my shoulder. Private equity firms used to take on undervalued companies, make them profitable and then walk away with a fair return. There was nothing wrong with that but they have gone brazen. They are now taking household names, valuable companies, stripping assets out of them and walking away with huge profits."

Nigel Hunton, chief executive of BOC Edwards, described CCMP as a "very professional outfit" and insisted its takeover of the company was "positive news".

He said: "There will be no job cuts linked to CCMP. They want to invest in us and have already committed spending to research and development.

They invest in companies with growth potential and that's what they see in us. The semiconducter market is set to grow by 20 per cent by 2008 with new technology on the market like iPods, satellite navigation and Microsoft Vista. That is not to say we can rule out restructuring of the business in the future but that will depend, as usual, on the performance of the business and for now it's business as usual."

He said CCMP had a "real understanding for the business and its potential" and its financial strength would support the company as it developed operations worldwide.

He said the deal with CCMP could lead to a stock market flotation in "two to three years".

Stephen Walton, from CCMP Capital, said: "We believe under CCMP's ownership BOC Edwards can move to a new level as an independent company and develop its technology in new markets while retaining leadership in its core areas."

Linde will receive a further £45 million when CCMP comes to sell BOC Edwards.

The transaction is expected to be completed in May or June, subject to a regulatory review. Last year BOC Edwards announced it was transferring 90 manufacturing jobs from its factory in Crawley, which employs 400 people, to the Czech Republic and India.

Private equity firms, which started to make a mark in Britain 25 years ago, now buy one in three companies sold and employ one in five people outside the public sector.

But there have been casualties along the way.

Permira is closing a Birds Eye fish fingers factory in Hull with the loss of almost 500 jobs after buying the brand from Unilever last year. In 2004, 900 jobs were axed at AA within days of a £1.75 billion takeover by Permira and CVC.

But the sector's trade body, the British Private Equity and Venture Capital Association, claims its members create jobs faster than other private sector companies.