McCain Foods Ltd. of New Brunswick has dropped its unfair trading complaint against several U.S. rivals in the frozen-pizza market.

The company, which had complained the U.S. companies were hurting the market by dumping cheap pizzas in Canada, refused to explain why it is backing down.

''This is a business decision,'' the company said in a statement from its headquarters in Florenceville, N.B. ''We are not prepared to discuss the specific reasons involved in arriving at this conclusion.''

Peter Clark, an Ottawa trade consultant, suggested McCain may have decided its chances of winning the dispute were slim.

''This looks like they have had an opinion from their (legal) counsel which suggests they would not be able to make their case or have a low chance of winning,'' Clark told the Toronto Globe and Mail in a report from Ottawa.

Canada slapped a temporary duty averaging 39.4% on frozen, self-rising pizzas from the U.S. in mid-May and is still investigating whether the levy is justified.

Ottawa was not expected to set a final duty on the U.S. imports until September.

That is when the Canadian International Trade Tribunal was scheduled to rule on whether the dumping of pizzas at discount rates was causing serious injury to producers such as McCain.

McCain had alleged U.S. pizza makers such as Kraft Foods North America Inc. are dumping frozen, self-rising pizzas at discount prices in Canada.