Rosyth Royal Dockyard, awaiting work from the multi-billion-pound government order for two new aircraft carriers, plunged to an operating loss of more than £5m last year.

Rosyth Royal Dockyard, awaiting work from the multi-billion-pound government order for two new aircraft carriers, plunged to an operating loss of more than £5m last year.

The number of staff employed at the yard during the year fell from 1081 to 971, with the loss of 146 production jobs, though administration gained 36 staff, according to a filing yesterday at Companies House.

It helps to explain the pioneering agreement earlier this year between Rosyth's owner Babcock International and oil services group Petrofac, enabling the two companies to share workers by offering retraining and job transfer to Rosyth workers when not needed by their principal employer.

Amicus, the UK's biggest manufacturing union, said it hoped the pioneering initiative would set a precedent for other sectors.

Two months ago, however, some 550 members of the Prospect union at the yard voted overwhelmingly in favour of industrial action in a dispute over pension cuts. The union said workers were being forced to make a 4.5% increase in pension contributions, and accept a cut in pensionable pay and a rise in the retirement age to 65.

The filing shows that the pension scheme saw its deficit slashed from £30.2m to £8.74m last year, in favourable equity and bond market conditions.

The dockyard was reporting its profit figures the day after a trading update from parent Babcock International put an estimate of £500m to £600m on the value to the group of the aircraft carriers, which will be assembled at Rosyth over the next eight years.

In the year to March 31, Rosyth Royal Dockyard saw a £700,000 loss the previous year plunge to £5.1m at the operating level. Other finance income, however, rose from £3.55m to £6.16m, resulting in a pre-tax profit of £1.02m, down from the previous year's £2.86m.

In Tuesday's statement, Babcock said Rosyth had won new business through "leveraging" its wide-ranging skills and engineering capabilities, including modular construction for utility systems for the new Birmingham General Hospital and ship conversions for the mining industry.

The yard has been part of the technical services arm of Babcock, which is now to run it in a new marine services division with its Faslane and Devonport yards.

On its new division, it has said negotiations are continuing with the Ministry of Defence "to establish a commercial framework which, once concluded, will be in place for a number of years".

The two 60,000-tonne aircraft carriers will be assembled at Rosyth after being built in sections on Clydeside, in Barrow, and in Portsmouth. They have a total value of £3.6bn and will help to support some 3500 Scottish jobs on sites which include BAE Systems' yards at Scotstoun and Govan on the Clyde.

Babcock said overall trading continues in line with its July expectations.