NatSemi shares tumble

Chip specialist National Semiconductor has suffered a severe hit in its share value, which nose-dived by 30 per cent after the company issued a revenue and profit warning.

Chip specialist National Semiconductor has suffered a severe hit in its share value, which nose-dived by 30 per cent after the company issued a revenue and profit warning.

National Semiconductor blamed a backlog in mobile phone handsets. The announcement follows similar warnings from Motorola and Ericsson