Management at the Seagate plants in Derry and Limavady have assured workers that the future of the Northern Ireland operation is not in doubt in spite of the closure of the company's plant in Clonmel.

"The Northern Ireland plants are involved in the production of recording media and recording heads," a spokesman said. "They are not involved in the production of the assembled disk drives. They will not be affected by this action."

Plans for the expansion of the Springtown facility in Derry have now been put on hold for at least six months. The company has said this is due to what it calls a "short-term lack of demand".

But Foyle MP Mr John Hume said he had spoken to Seagate senior vice-president Dr Brendan Hegarty, who told him that the Clonmel decision would not affect Derry or Limavady, and that the expansion of the Springtown operation would eventually go ahead.

Seagate, which was set up in 1974, has a turnover in excess of $8 billion (£5.5 billion), and employs over 100,000 people worldwide. The Derry plant was opened in 1993 and employs more than 1200 people. A high proportion of them are engineering and electronics graduates, involved in a highly sophisticated process manufacturing the magnetic recording heads which read or write the data on to the computer's hard disk.

These "read/write heads" are then sent on to the Far East for the next stage in the process, before the various parts of the disk are returned to Clonmel for final assembly.

The company has now decided that it can carry out this assembly process much more cheaply in the Far East. What is not clear is why they reached this conclusion only two a half years after the announcement that they were setting up in Clonmel.