CHICAGO (CBS) — As Mayor Rahm Emanuel searches for a new leader for the Chicago Public Schools, he also has decided to replace most of the school board that approved a controversial $20.5 million no-bid contract which is the focus of a federal investigation.

Former CPS Chief Executive Officer Barbara Byrd-Bennett has stepped down, amid a federal probe into a principal training contract awarded to her former employer, SUPES Academy, and Board of Education Vice President Jesse Ruiz has been serving as acting CEO since she started a leave of absence in April.

Four of the seven members of the Chicago Board of Education have terms that expire at the end of June, and, Emanuel will not renew their appointments. Instead, the mayor has decided to replace board members Deborah Quazzo, Andrea Zopp, Carlos Azcoitia, and Henry Bienen with retiring Loyola University president Rev. Michael Garanzini, retiring BMO Harris Bank CEO Mark Furlong, Chicago Scholars foundation president Dominique Jordan Turner, and former Walter Payton College prep principal Gail Ward.

Quazzo has been the focus of her own controversy, due to her investments with companies that do business with the district. According to published reports, companies in which Quazzo has a financial stake have seen their business with CPS triple since Emanuel appointed her to the school board.

Zopp has announced plans to run for the U.S. Senate in 2016.

The Chicago Teachers Union and many parent groups have called for an elected school board, but Emanuel has resisted that idea.

Meantime, the mayor told the Chicago Tribune he is in no rush to find a permanent replacement for Byrd-Bennett, as having Ruiz in place gives him time to conduct a thorough search. He said the next CEO for the district will need solid educational and financial expertise.