McDonald's Corp. (MCD) on Wednesday said sales at its hamburger restaurants open at least 13 months rose 4.7 percent in February thanks to strong sales of a new spicy chicken sandwich in the United States, its biggest market.

Three Wall Street analysts had been expecting an increase of 3.5 percent to 4.8 percent, according to research reports.

"We posted positive comparable sales across all geographic segments for February and marked our 34th consecutive month of positive global comparable sales performance, McDonald's Chief Executive Jim Skinner said in a statement.

Same-store sales rose 3.6 percent in the United States, driven by the popularity of new chicken sandwiches and breakfast choices and by extended hours.

Sales climbed 5.4 percent in Europe, the company's No. 2 market, driven by demand in Germany and France.

Analysts had forecast a rise of 4 percent to 5.5 percent in the United States and an increase of 3 percent to 5 percent in Europe.

Shares of McDonald's rose 0.5 percent to $34.82 in premarket trade on the Inet electronic network, up from a close of $34.64 on the New York Stock Exchange on Tuesday.