Apple is buying P.A. Semi, a designer of low-power microchips, in a move that could bolster its ability to customize key parts for its iPhone, iPod and Macintosh product lines.

The deal, first reported on the Forbes magazine Web site, was confirmed on Wednesday by Apple, although no furhter details were unveilled.

Forbes said the transaction was valued at $278 million in cash.

Apple already employs many semiconductor experts who work closely with partners to customize chips to make its products stand apart. The move could help Apple bulk up their system design teams to enhance their ability to work with third-party vendors.

Key Apple partners include Intel, which supplies the processors for Mac computers, and Samsung, which makes the iPhone processor.

P.A. Semi, which launched its first products in late 2005, has a family of chips based on the Power architecture from IBM but that use far less electricity than other designs.

P.A. Semi said its chips could be used in everything from printers to video game systems to supercomputers. It is a "fabless" chip company, meaning it uses contract manufacturers and does not own its own production facilities.