Richard G. Ketchum was named chief regulatory officer at the New York Stock Exchange, effective June 2. The position is new. Mr. Ketchum currently is general counsel of the corporate and investment bank of Citigroup Inc., New York. He also is a past president of Nasdaq and the National Association of Securities Dealers. Edward Kwalwasser, NYSE group executive vice president of regulation, will run the exchange's regulation department until Mr. Ketchum joins. Mr. Kwalwasser will retire on Oct. 1.