Over 4,000 workers in Bombardier Aerospace, Northern Ireland's biggest employer, yesterday began an all-out strike.

They are protesting against a proposed four-year pay-freeze which the multinational wants to implement at its four Belfast plants as part of a group-wide cost-saving plan.

The strike follows the break down in talks between management at the plant and its unions, Amicus and the Transport and General Workers Union (TGWU). The company has already cut 600 jobs this year and a further 300 are under threat.

Montreal-headquartered Bombardier lost 600 million Canadian dollars last year (€386 million), and has sold off a number of non-core assets as part of its restructuring plan. It warned earlier this year that 1,000 jobs would have to go at Belfast if the pay freeze is not implemented.

Meanwhile, Bombardier said it had revised last year's financial statements because of an accounting error, and its shares fell 5 per cent for a second day.

It said the restatement had no impact on overall results for the 2002-03 financial year, which ended on January 31st. But it revised results for individual quarters. "It's really a non issue," said Mr Cameron Doerksen, analyst for Dlouhy Merchant.

He said the share price drop had more to do with the strike at Bombardier's Belfast plants, which could crippled the firm's regional jet deliveries if it is not settled quickly.