Richard Ketchum is resigning his role as president and deputy chairman of The Nasdaq Stock Market Inc.

He will leave the company effective June 17 to become general counsel with Citigroup’s Global Corporate & Investment Bank. “Nasdaq is losing an outstanding man in Rick Ketchum,” noted Wick Simmons, chairman and CEO. Simmons is also leaving the exchange.

Effective May 12, Robert Greifeld and H. Furlong Baldwin will assume the positions of president and CEO and non-executive chairman of the board, respectively.