Sales at McDonald's (MCD) established hamburger restaurants rose 3.4 percent in August on strong U.S. demand for a new line of higher-priced chicken sandwiches, the company said on Friday, sending its stock higher.

Same-store sales, which measure results at restaurants open at least 13 months, were at the low end of Wall Street expectations for a rise of 3 to 6 percent. Still, Banc of America Securities analyst Andrew Barish said they were impressive, given strong U.S. results last year.

U.S. same-store sales were up 3.2 percent for the month, following a 7.2 percent increase in the same period last year.

The period, which ended August 31, largely excluded the impact of Hurricane Katrina (search), which ravaged the Gulf Coast on August 29. McDonald's Corp officials were not immediately available to say how many of the chain's fast-food outlets remained closed due to the storm; 130 restaurants were closed as of September 5.

Same-store sales in Europe, where McDonald's has been working to revitalize its business, climbed 3.6 percent. Strong sales in France and Germany helped offset continued weakness in the United Kingdom, Oak Brook, Ill.-based McDonald's said.

Several U.S. consumer companies have struggled recently with weak sales in Europe due to economic softness and the growth of discount retailers.

Soft drink bottler Coca-Cola Enterprises Inc. (CCE), for one, said on Thursday its earnings would miss Wall Street forecasts due to sluggish shipments in Europe.

McDonald's has boosted sales in Germany in recent months thanks to new menu items and marketing promotions. In the United Kingdom, however, the company suffers from poor perception of its food that McDonald's is working to reverse.

Same-store sales were up 4 percent in McDonald's Asia/Pacific, Middle East and Africa region, the company said.

Total sales in August rose 5.7 percent; excluding the impact of a weaker U.S. dollar, they were up 4.4 percent.

McDonald's shares rose 91 cents, or 2.7 percent, at $34.28 on the New York Stock Exchange. The stock is up 8.6 percent so far this year, compared with a 1.7 percent fall in the Standard & Poor's Restaurants Index (search), of which it is a component.