The appointment by SEC Chairman Christopher Cox fills a high-level position at the agency that has been vacant for more than six months, with an acting chief accountant in the post. The chief accountant oversees guidance and interpretations issued by the SEC, which can have an impact on public companies' practice.

In March 2005, for example, the chief accountant's office issued guidelines that allowed companies some latitude in measuring the value of employees' stock options - which must be counted against corporate profits. Companies were told that to a reasonable extent, they didn't all have to use the same methods to value options.

The office is expected to provide guidance for companies on putting into effect internal financial controls under the 2002 anti-fraud law that arose from the wave of corporate scandals.

Hewitt, 69, will assume the job on Aug. 18. He heads the board of directors' audit committees at Varian Inc., a maker of scientific instruments and vacuum products, and at North Bay Bancorp. He also is chairman of both the audit committees and compensation committees at S&P Co., the parent of Pabst Brewing Co.

Hewitt was the top financial regulator in California from 1995 to 1998, and was a managing partner of major accounting firm Ernst & Young from 1972 to 1995.

Originally from Sheffield, Ill., he has a bachelor's degree from the University of Illinois and did graduate work at the University of Southern California.