Osvaldo V. Librizzi, co-president of the Americas for Starwood Hotels & Resorts, will retire at the end of this year and will stay on as nonexecutive chairman until the end of 2015, the company announced Tuesday. Librizzi's fellow co-president, Sergio Rivera, will become president of the Americas and will take on full responsibility for the region. The current senior vice-president and CFO of the Americas region, Jorge Giannattasio, has been appointed to the new role of chief of Latin American operations and global initiatives. This summer he will begin to oversee regional operations. Both he and Rivera will work closely with Librizzi throughout this year, to ensure a smooth transition upon Librizzi's retirement.