Hamburger chain Wendy's Co knocked Burger King Corp from its spot as the second-largest U.S. hamburger chain in 2011, but sales of both companies continued to lag McDonald's Corp , the country's No. 1 restaurant chain.

The combined revenues of Wendy's and Burger King came to just under $5 billion last year, when total revenue at McDonald's rose 12 percent to $27 billon, according to earnings statements from the companies.

McDonald's menu appeals to a wider range of customers, and it has used its financial heft to buy ingredients like ground beef at lower prices than many of its rivals.

Subway remained the second-largest restaurant chain in the United States last year, according to a report by consulting firm Technomic.

Starbucks Corp came in at No. 3, followed by Wendy's and Burger King, according to Technomic.

Technomic found that overall sales for the top 500 U.S. restaurant chains grew 3.4 percent to an estimated $242 billion in 2011. That compared with an 1.8 percent rise posted in 2010.

Five Guys Burgers and Fries was the fastest-growing U.S. chain with sales over $200 million, followed by burrito chain Chipotle Mexican Grill and Jimmy John's Gourmet Sandwiches, Technomic said.

(Reporting By Lisa Baertlein in Los Angeles)