ORANGE COUNTY

Philip Frey Jr., president and chief executive of Microsemi Corp. in Santa Ana since 1971, has been given the additional duties of chairman, the company announced.

Frey, 59, who has orchestrated the company’s spectacular growth in the last three years, replaces Richard L. Geiger, who had served as chairman since 1971.

Geiger, 69, said he was stepping down to assume the newly created position of vice chairman because he wanted to “step back from the responsibilities . . . and allow . . . senior management to assume greater responsibilities within the company.” Geiger has been with the company since 1960.

Microsemi is a semiconductor maker and defense contractor.