Wendy's U.S. company-owned stores were down 3.5 percent, while franchised locations were down 1.5 to 2.0 percent.
Tim Horton's, meanwhile, posted postive comps in both the U.S. (2.5 to 3.0 percent) and Canada (4.5 to 5.0 percent).
"The weather during January was significantly worse than a year ago," said Wendy's chairman and chief exec Jack Schuessler in explaining the negative comps. "In addition, discounting in the quick-service restaurant industry continued during the month.
"We focused our national advertising at Wendy's on the variety of quality food available on our 99-cent Super Value Menu. In February, we have several exciting new products in market tests across the country.
"Tim Hortons was effective with its national advertising highlighting coffee and fruit muffins during January. In February, Tim Hortons will feature the new Big Baguette sandwiches," Schuessler said.
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