The plant, at Filton near Bristol, has struggled since the air industry slump in the wake of the 11 September terrorist attacks.

At one stage the plant employed 500 people and won a huge £100m order to convert 31 planes from a United States leasing company.

BAE Systems had tried to find a buyer for the site, which was set up originally to maintain military aircraft.

'Staff jobs'

Managing director Cliff Duke said: "It is not entirely 11 September which is to blame.

"We were experiencing a rundown before then and despite our best efforts to find a buyer for the business we just have not been successful.

"We just can't sustain the losses anymore and are going to close the business.

"What we are now doing is devoting our efforts to trying to find as many jobs for the staff as possible, both within BAE Systems Group and within Airbus UK.

"I am very sad. The staff have done a tremendous job managing to secure contracts right across the world.

"There just isn't a clear way out of this downturn we are in at the moment."