<PAGE>
EXHIBIT 99.1
[POWER-ONE, INC. LETTERHEAD]
POWER-ONE DECLARES THREE-FOR-TWO STOCK SPLIT
CAMARILLO, Calif. - May 10, 2000 - The Board of Directors of Power-One Inc.
(Nasdaq: PWER) at its meeting, May 9, 2000, declared a three-for-two stock
split of the company's common stock.
The stock split will be effected in the form of a 50 percent stock dividend
payable June 2, 2000, to stockholders of record May 24, 2000. The dividend
will increase the number of outstanding shares to about 36.4 million from
about 24.3 million.
Power-One is a leading manufacturer of power conversion products designed
primarily to power the Web.
Power-One, with headquarters in Camarillo, has more than 4,000 employees with
manufacturing operations in Irvine, Calif.; Boston; Mexico; Dominican
Republic; Puerto Rico; Switzerland; Ireland; Slovakia; and China. For
information on Power-One and its products, visit the company's Web site at
WWW.POWER-ONE.COM.