McDonald's Corp said on Friday that January sales at established hamburger restaurants around the world fell 1.9 percent, as fast-food chains fight hard for diners, who continue to spend cautiously due to lackluster economic growth in most major markets.

McDonald's warned last month that same-restaurant sales would be down. Analysts polled by Consensus Metrix had expected a decline of 1.1 percent.

(Reporting by Lisa Baertlein in Los Angeles and Jessica Wohl in Chicago; Editing by Gerald E. McCormick)