Two days after authorities in Brazil raided Whirlpool Corp.'s (WHR) offices there, the U.S. Department of Justice confirmed Thursday that it is investigating possible antitrust violations in the multibillion-dollar refrigeration compressor industry, in conjunction with international authorities.

"The Antitrust Division is investigating the possibility of anticompetitive practices in the compressor industry," said Justice Department spokeswoman Gina Talamona. "We are coordinating with other foreign competition authorities."

Whirlpool said Thursday that it received a grand jury subpoena Tuesday from the U.S. Justice Department seeking company documents. The company confirmed that Brazilian and Italian authorities visited Whirlpool offices in those countries on the same day.

Whirlpool said it would cooperate fully with the investigations and said that, to the company's knowledge, there have been no charges filed against the company or any of its employees.

Tecumseh Products Co. (TECUA), a Whirlpool competitor, said Wednesday that it, too, has received a grand jury subpoena from the U.S. Justice Department. Tecumseh said it also has received investigatory requests from Brazilian authorities and believes the European Commission is conducting an investigation. The company said authorities appear to be focusing on pricing issues.

Brazilian authorities swept through Whirlpool's Sao Paulo and Santa Catarina state offices Tuesday in an operation called Zero Grau, or Zero Degrees, with the objective to find evidence of a global cartel in the selling of hermetic compressors for refrigeration. The compressors are used in household refrigerators and freezers, as well as commercial vending machines and water coolers.

Sixty agents left with bags full of computers, laptops and other archival material.

Raymond James cut its rating on Whirlpool Thursday based on news of the investigation. "An investigation may aversely affect Whirlpool's ability to achieve pricing in its core white goods business in 2009, which is critical to its defraying input cost inflation and un-absorption rates," the firm said.

Whirlpool's compressor business is handled by a corporate subsidiary called Embraco that operates as a separate company, supplying compressors for Whirlpool brands as well as the appliance maker's competitors.

With annual sales of about $1.5 billion, Embraco is estimated to control as much as 25% of the global market for refrigerator compressors.

"Anywhere there's a refrigerator in the world there's a one-in-four chance that it has an Embraco compressor in it," said Sam Darkatsh, a Raymond James analyst.

In Brazil alone, Embraco supplied compressors for more than 50% of the refrigerators sold last year, according to market research firm Euromonitor International. Unit sales of refrigerators in Brazil had been growing by an average of 11% a year since the 1990s. But tight credit and a downturn in the economy have put a damper on appliance sales.

Industry observers say Embraco, Tecumseh and other compressor companies have been reluctant to slash their prices to generate order volume during the downturn, raising customers' suspicion that the companies had engaged in price fixing. Embraco's operating profit margins have remained steady at 8% to 10%.

Whirlpool has said it intends to raise its prices on appliances by 7% to 10% this year. With an investigation of Embraco now under way, retailers may have the leverage needed to reject higher prices from Whirlpool, said Darkatsh, who lowered his rating on Whirlpool's stock Thursday to "outperform" from "strong buy."

"It throws a complication into the mix," he said.

-By Brent Kendall, Dow Jones Newswires; 202-862-9222; brent.kendall@dowjones.com

(Kenneth Rapoza contributed to this report.)