NYT – The chairman of Citigroup’s Mexico operations, Manuel Medina-Mora, is retiring in June, after a tumultuous year at one of the bank’s most profitable units. Medina-Mora, who joined Citigroup in 2001 when the bank bought the Mexican bank Banamex, rose through the ranks to become co-president and head of global consumer operations. But after a series of scandals rocked Banamex last year, raising concerns about lax controls in Mexico, Citigroup executives in New York began preparing for Medina-Mora’s departure.