Toshiba has announced that it is to buy Fujitsu's hard disk drive business. Initially, Toshiba will acquire about an 80% stake in the business and make it a Toshiba Group subsidiary.

In order to "promote a smooth transfer", Fujitsu will then continue to hold a stake of under 20% for a certain period of time, after which it will become a wholly owned subsidiary of Toshiba.

The move will give Toshiba a strong position in the 2.5-inch and under HDD market, devices widely used in notebook PCs, mobile devices, automotive and consumer electronics. The company says this move is expected to "spur" expansion of the rapidly expanding SSD market.

The companies plan to complete the transaction in the first quarter of fiscal 2009 - financial terms were not disclosed, but are thought to be over $900 million.