Washington ? President Bush chose California Rep. Christopher Cox on Thursday to run the Securities and Exchange Commission, assigning him the regulatory dance of protecting investors’ rights while not stifling business.

Cox, a conservative 16-year veteran of the House, would replace William Donaldson, a Republican who turned out to be a firm regulator and often clashed with GOP business allies during his 2 1/2 years at the helm. The White House announcement came one day after Donaldson, 74, said he would leave at the end of this month.

Business groups, which view some SEC regulations as overly burdensome and would like to see them loosened or overturned, welcomed Bush’s pick. Advocates for individual investors voiced concerns that Cox might do just as business hopes.

The SEC position is subject to Senate confirmation, a process that left Cox bruised once before.

He was in line for an appointment to the U.S. Court of Appeals in 2001 when Democrats temporarily gained control of the Senate. Facing opposition from at least one of his home state’s two Democratic senators, Cox realized he faced a difficult fight to win confirmation to the bench without a guarantee of success. He withdrew his name.

Senate Minority Leader Harry Reid, D-Nev., who praised Donaldson’s activist stance, said he hoped Cox’s confirmation hearing would shed light on the direction the nominee would take the SEC. Cox will have “big shoes to fill,” in his bid to replace Donaldson, Reid said.

The agency, which is responsible for protecting investors and maintaining the integrity of the securities markets, has come under heightened attention since a wave of corporate scandals in recent years – including Worldcom, Enron and Tyco – rocked Wall Street and shook investors’ confidence. Donaldson was brought on board to restore that confidence.

“Bill Donaldson has set high standards for American business and the SEC,” Bush said. “Chris Cox is the right man to carry on this important work.”