Workers are voting on suggested pension changes

The firm said 54% of pension fund members had voted in recent ballots in favour of a proposal to change the terms of the group's main "final salary" scheme.

The company's pension scheme had a �1.1bn deficit at the end of 2002 under the new "snapshot" accounting standard, which does not allow firms to smooth out stock market volatility.

Rolls-Royce said on Tuesday that the package that had been approved involved a balance between reduced member benefits and increased company contributions.

Rising deficit

The group, which has sites in Derby, Bristol, Glasgow, East Kilbride, Coventry, Lancashire and Sunderland, will increase its annual contribution to the fund from �60m to �95m under the new system, a spokesman said.

Employees had to accept a proposal to reduce their accrual rate from 1/60th of their final salary for every year of membership of the scheme to 1/80th.

Today's yes vote by the trade union members of the pension fund is the end of a long and difficult process Steve Wright Union chairman

Less generous early retirement benefits and changes to additional voluntary contribution arrangements also form part of the package.

The company's main pension fund, which has been closed to new members since 1999, has 18,000 active members, 16,500 deferred members and 40,000 retired members.

The firm's human resources director John Rivers said: "The proposal that has been accepted achieves the right balance between increased company contributions and reductions in member benefits."

Chairman of the Rolls-Royce trade union central negotiating committee, Steve Wright, said: "Today's yes vote by the trade union members of the pension fund is the end of a long and difficult process that has seen Rolls-Royce meet many of the union's demands."

Many companies with final salary pension schemes are facing deficits due to stock market falls and increased life expectancy.