WASHINGTON – Bayer AG has agreed to plead guilty and pay a $66 million fine for its part in an international rubber chemical price-fixing cartel, the Justice Department said Wednesday.

The plea by Bayer, based in Leverkusen, Germany, was entered in court papers filed in U.S. District Court in San Francisco.

Bayer becomes the second company to plead guilty as part of the conspiracy. In May, Crompton Corp. of Middlebury, Conn. – parent of Uniroyal – agreed to pay a $50 million fine in the case.

Prosecutors say the conspiracy involved additional unnamed companies and centered on fixing prices for additives and fillers used to improve the elasticity, strength and durability of rubber products such as tires, outdoor furniture, hoses, belts and shoes.

“Today’s plea is an important step in our prosecution of a cartel that harmed millions of American consumers who use a broad spectrum of products manufactured with rubber chemicals,” said R. Hewitt Pate, assistant attorney general for the Justice Department’s antitrust division.

About $1 billion in rubber chemicals are sold each year in the United States.

Bayer pleaded guilty to a single felony charge of violating the federal Sherman Act. Prosecutors say Bayer was among several companies that sought to eliminate competition for rubber chemicals sold in the United States from 1995 to 2001.

Prosecutors say the investigation, based in San Francisco, is ongoing.

“The company charged today will provide valuable assistance in our continued investigation in the rubber chemicals industry,” said James Griffin, the top Justice Department deputy for antitrust criminal enforcement.

Bayer officials did not immediately respond to a request for comment.