The factory in Thatcham, Berkshire manufactures mobile phones mainly for the European market.
Matsushita will shift its European mobile phone production to a factory in the Czech Republic from April 2002, said Yasuharu Enda, a spokesman for the company.
"The pound is becoming more expensive, which is tough for a Japanese company," Enda said. "But most of all, sluggish demand is the reason. Inventory is increasing and we need to move our production base to the Czech Republic where labour costs and taxes are lower."
Matsushita has an affiliate company and two factories in the UK. In March, the company announced that its other plant, a mobile phone packaging plant in Portsmouth, would close in March 2002.
However, the research and development centre at the Thatcham plant, which was opened in April this year, will continue development work on 3G handsets, Enda said.
Some 550 jobs - 350 from Thatcham and 200 from Portsmouth - will be lost as a result of the plant closings.