The 500 largest US restaurant chains registered a 3.5% annual sales increase in 2013, a significant decline from 4.9% the prior year, according to data released by Technomic.

The foodservice consultancy found that US systemwide sales for the Top 500 chains grew to an estimated $264bn in 2013, up more than $8.8bn over 2012.

“Although we have seen overall growth within the Top 500, the pace has slowed since last year,” said Ron Paul, President of Technomic. “Competition for share of stomach is getting more and more challenging. But brands that have found a way to differentiate themselves are gaining market share.”

Among limited-service restaurants, the highest growth came from the Asian, bakery café and coffee café categories. Segment leaders were Panda Express (10.7% sales growth), Panera Bread (11.8%) and Starbucks (10.6%). McDonald’s, the largest US restaurant chain, saw minimal sales growth of 0.7% in 2013, to reach annual sales of $35.9bn. Subway continues as the second largest restaurant chain in the U.S., followed by Starbucks, Wendy’s and Burger King.

As a whole, limited-service restaurants saw a sales increase of 3.9%. Chicken chains, which grew 5.1%, represented another limited-service sub segment with above-average sales growth. Chick-fil-A grew 9.3% with 2013 sales of $5.1bn and surpassed KFC as the top chicken chain.

Full-service restaurants experienced a 2.4% sales increase in 2013, a slight decrease over the 2.9% seen in 2012. The full-service steak category continued to show healthy growth, with an increase of 6.2%. Gains in the steak category were driven by Texas Roadhouse (11.1%) and LongHorn Steakhouse (12.8%). Among varied-menu chains, which increased sales by 2.5% overall, the category leader, Buffalo Wild Wings boosted sales 12.9%.

More than 67% of the Top 500 restaurant chains posted at least nominal sales increases. Only 156 of Top 500 chains suffered sales declines in 2013 compared to 168 in 2012.

The company said: “Both winners and losers appeared in every segment and menu category. These widely mixed results demonstrate the overall competitiveness of the industry and the need for suppliers and operators to carefully identify and focus on the winners.”

International performance by the Top 500 restaurant chains continued to outperform domestic growth in 2013. International sales increases (4.4%) outpaced U.S. sales growth (3.5%); international unit growth was up 9% versus 2.2% for US units.