$3 billion CIT Group, a provider of financing to small businesses and middle market companies, has elected John Thain to serve as chairman and CEO. He replaces Peter Tobin, who has been acting as interim CEO, and who will remain a director for the company.

In his new role, Thain will continue to help with CIT's transition to a more streamlined commercial lender focused on serving the small-business and middle-market sectors and optimizing the company's business model. Thain previously served as chairman and CEO of Merrill Lynch until its sale to Bank of America.

Prior to that, Thain held the position of CEO of the New York Stock Exchange, where he presided over the exchange's global transformation into a publicly traded entity. Thain spent the majority of his career at Goldman Sachs Group, where he rose to president and chief operating officer.