Nissan's Sunderland plant employs almost 5,000 people

The move follows an earlier announcement that the company, which employs about 5,000 people at its plant on Wearside, had a �121m pensions shortfall.

The company had originally planned to put �30m into the fund.

Now the company has agreed to put a further �20m into the fund, which it says will ease the financial burden on workers.

The cash will be used to bolster the company's final salary scheme, which is to be closed to new members from September.

The move will still mean workers will have to pay higher contributions and are likely to receive a smaller pension when they retire.

Difficult time'

The company said it decided to plough in extra cash after discussions with its employee council on Wearside.

A spokesman said the company's plan to increase its contribution into the scheme from 12% to 16% of the payroll would remain unchanged.

Philip Ashmore, the company's personnel director, said: "During the consultations, the company council has been fair, but very determined in asking Nissan to bear more of the cost of the pension fund.

"This is a time that has proved difficult for all UK pension funds, given the current investment environment.

"However, the cash injection of �50m underlines Nissan's commitment to safeguarding its final salary scheme for all of its existing members."

In 2002 the company produced 297,000 vehicles in its Sunderland factory, the largest car manufacturing plant in the UK.