New Citigroup (C) CEO Michael Corbat continued his shakeup at the No. 3 U.S. bank with the promotion of a pair of executives to co-presidents. Jamie Forese, a former divisional CEO, will now be responsible for all of Citi's institutional businesses. Manuel Medina-Mora, head of the consumer banking business, will continue to oversee that business as well as Citi's Mexico business. The two replace John Havens, the president and chief operating