Power One


was down 27% in preopen


trading after it cut revenue and earnings guidance for the year due to the slowdown at some of its largest customers, chiefly


(CSCO) - Get Report


Power One, which makes power conversion devices, said first-quarter results will be close to current expectations, but the rest of the year looks doubtful.

The company also said it would speed up its cost-reduction efforts, including moving jobs out of North America and Europe.