Wendy's/Arby's Group Inc., the third largest U.S. fast-food chain, said Monday it posted a quarterly loss of nearly $400 million due to recent negative trends in operating performance, the downturn in the economy and adverse stock market conditions.

Wendy's/Arby's posted a loss of $393.2 million, or 84 cents per share, for the fourth quarter ended December 28, compared with a profit of $33.3 million, or 33 cents per share, a year earlier, according to the reports.

Both chain revenue results during this quarter was $896.5 million, as sales at North American restaurants rose 3.7% at Wendy's and fell 8.5%at Arby's.

Hamburger seller Wendy's brand was bought last year for just over $2 billion by Triarc, the owner of the Arby's sandwich chain to form Wendy's/Arby's.