McDonald's said on Friday that January sales at established hamburger restaurants around the world fell 1.9 percent, a steeper decline than analysts expected, as fast-food chains fight hard for diners.
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.
Shares of McDonald's, which had fallen earlier in the week, slipped in premarket trading.
McDonald's expected its sales and profit growth to be under pressure in the near term, as diners continue to spend cautiously due to lackluster economic growth in most major markets. At the same time, the leading fast food chain is also bumping up against strong results from a year ago, including a 6.7 percent gain in comparable sales in January 2012.
Comparable sales in Europe, McDonald's top market, declined 2.1 percent last month, with weakness in countries such as Germany and France.
The United States, a close No. 2, posted a 0.9 percent gain, helped in part by the addition of the Grilled Onion Cheddar burger to the company's Dollar Menu.
Asia/Pacific, Middle East and Africa (APMEA) turned in a 9.5 percent decline. McDonald's cited issues such as continued weakness in Japan and in China the shift in the timing of the Chinese New Year.
Analysts expected Europe to be up almost 0.1 percent. They expected the United States to be down 0.3 percent and APMEA to be down 5.8 percent.
McDonald's comparable sales track sales at all company-owned and franchised restaurants open for at least 13 months.