Whirlpool Stock Falls on News of U.S. Antitrust Investigation : Pricing: Appliance maker has been most aggressive price raiser in industry. Jilted customer Best Buy leaked word of the probe.

In an unusual display of corporate tit-for-tat, Best Buy Co. seems to have extracted some revenge on Whirlpool Corp. for dropping Best Buy as a customer.

Whirlpool’s stock fell in heavy trading Friday after word leaked out that it was the subject of a federal antitrust probe.

The leaker was its jilted former customer, Best Buy.

The Justice Department confirmed the existence of a probe. “The antitrust division has an ongoing investigation of pricing practices in the large home-appliance industry,” spokeswoman Gina Talamona said. She declined to be more specific.

County Natwest analyst Nicholas Heymann said the probe, disclosed Thursday, could make it difficult for Whirlpool to raise prices, something the company needs to do to protect its profits in the face of new challenges from low-cost producers.

Heymann said Whirlpool has been the most aggressive appliance maker about raising prices in the United States and Europe, but the gains have been largely offset by heavy promotional expenses.

Whirlpool recently told analysts it intends to reduce promotional spending, but it is unclear if retailers will accept higher prices.

The electronics retailer’s stock plunged Thursday after it released a disappointing third-quarter earnings forecast, then fell even further after a report that Whirlpool would no longer supply its Whirlpool appliances to Best Buy.

After the close of trading Thursday, during which Best Buy shares plummeted 26%, the Minneapolis-based company issued a news release confirming its falling out with Whirlpool.

But tucked into the release was a previously undisclosed fact that Best Buy was privy to as a major appliance retailer: Whirlpool is a subject of a federal antitrust investigation.

Whirlpool spokeswoman Robin Skiles said the company decided to stop selling its Whirlpool brand through Best Buy because Best Buy operates largely as a discount warehouse operation and this conflicts with Whirlpool’s strategy.

“If we put them into a distribution channel that is a price-value channel, it’s a conflicting message for our brand,” Skiles said.

In terms of the government probe, she said Whirlpool believes the investigation is focusing on several appliance makers and said Whirlpool is cooperating fully.

Whirlpool shares fell $2.25 Friday to close at $46.50, on volume of 1.08 million shares.