Hamburger chain Wendy's Co
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.
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
(Reporting By Lisa Baertlein in Los Angeles)