The merger of Ernst & Whinney and...

The merger of Ernst & Whinney and Arthur Young & Co., two of the nation’s Big 8 accounting firms, has created the largest accounting office in Orange County, said Gary D. Johnson, local manager of what is now called Ernst & Young.

The local operation has 25 partners among 353 employees, Johnson said, and eventually will join forces in one of its client’s buildings, probably in Koll Center Irvine where Ernst & Whinney is located.

Before the merger, the Big 8 firm with the largest presence in the county was Peat Marwick Main & Co. with about 270 employees in its Costa Mesa office.

Johnson said Ernst & Young will concentrate on servicing firms in real estate construction, manufacturing and high technology, health care, financial services and retail. He said those areas should generate more than half the revenue for Ernst & Young’s Orange County office.

Johnson, who had managed the Arthur Young office in Costa Mesa, has become managing partner of the county office. He also will oversee about 250 other employees at Ernst & Young’s offices in San Diego, Riverside and Rancho Cucamonga.

Thomas R. Testman, who ran Ernst & Whinney’s Irvine office, has moved to Los Angeles as managing partner of the firm’s western regional management consulting group. In the late 1970s, Testman had headed Ernst & Whinney’s national consulting practice.