The US Department of Justice is contacting chocolate manufacturers in the US to find out whether there is any evidence of price fixing in the confectionery market.

The department has contacted Mars, the confectionery giant, about the way in which it prices the chocolate that it sells.

It is not known whether Cadbury Schweppes, the UK group, has been approached by the US authorities.

Canadian cartel investigators launched an inquiry last month into whether Hershey, Nestlé and Cadbury had conspired to fix prices.

Chocolate makers have had a bad year.

Surging raw material costs have hit profit margins with the price of milk and fuel surging throughout the year.

The impact of rising prices has been so severe that Hershey, the maker of Hershey Kisses, was forced to give warning that profits would be lower than expected.

A spokesman for Mars was reported as saying that the owner of Snickers and M&M sweets had been contcted by the US Department of Justice as part of its inquiry into the pricing of chocolate in the US.

The company said that it intended to co-operate with the department in the event that it launched a formal inquiry.

Last month the Ontario Superior Court of Justice issued search warrants to chocolate makers "based on evidence that there are reasonable grounds to believe that a number of suppliers in the chocolate confectionery industry have engaged in activities contrary to the conspiracy provisions of the Competition Act.

"There is no conclusion of wrongdoing at this time and no charges have been laid."

It is not yet clear whether the US Department of Justice's preliminary inquiries will lead to a formal investigation.

However, cartel activities are treated seriously in America, attracting heavy fines and, in some cases, prison sentences for executives.

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