We know how hard this can be on our employees and their local communities

Levi's chief executive Philip Marineau

Levi Strauss said it was in discussions with unions over the terms of severance packages for the workers to be laid off when the plants close.

The closures are part of the company's policy of shifting away from manufacturing its products in-house.

Chief executive officer Philip Marineau said: "There is no question that we must move away from owned-and-operated plants in the US to remain competitive in our industry.

"At the same time, we know how hard this can be on our employees and their local communities."

He said the company was to provide a benefits package those laid off that was "well above industry norms".

The plants will close in three phases over the year, with two of those affected closing in June, two more in August and the final two in October.

Tough competition

The company's two remaining US owned-and-operated manufacturing facilities - a sewing plant and a finishing centre in San Antonio, Texas - will continue to operate.

Levi Strauss is one of the world's largest clothing brands, with 2001 sales of $4.3 billion (�3bn).

The company manufactures and markets branded jeans and casual sportswear under the Levi's and Dockers brand names.

Last month, Levi's announced it was to close two factories in Scotland, with the loss of 650 jobs.

The company has been shifting production away from the US since 1999, when it shut half its North American plants.

Levi's dominated the jeans market in the 1980s and early 1990s, but has slipped in the face of competition from younger, more fashionable brands and the decline in the popularity of traditional blue jeans.

The company's business plan has shifted to marketing and product development and away from manufacturing as it bids to reclaim its place at the peak of clothing retail.