President Bush reportedly is expected to name Wall Street executive William Donaldson as the new chairman of the

Securities and Exchange Commission

.

Media reports said an announcement was planned for later Tuesday. Donaldson would replace SEC Chairman Harvey Pitt, who resigned in November amid a slew of corporate scandals.

Donaldson founded the investment banking firm Donaldson Lufkin & Jenrette. He also served as chairman and chief executive of the

New York Stock Exchange

from 1990 to 1995. He was a founder of Yale University's Graduate School of Management.

Bush's expected selection of Donaldson comes a day after he nominated railroad executive John Snow for the post of Treasury secretary, replacing Paul O'Neill.