Visteon Corp., the world’s fourth-largest auto-parts maker, was accused in a lawsuit by Tenneco Automotive Inc. of infringing two patents for catalytic converters. As reported in the Bloomberg news service, Tenneco, the world’s largest maker of exhaust systems, claimed in a federal lawsuit in Wilmington, Delaware, that its competitor intentionally used Tenneco’s inventions for the devices that reduce automobile pollution. “Visteon is making unlawful gains and profits from its infringement,” Lake Forest, Illinois-based Tenneco said in its complaint, which asks for a jury trial and unspecified damages. In the U.S. market alone, mechanics install 34.8 million catalytic converters in older cars each year, according to Margaret Beck, communications manager for the Motor & Equipment Manufacturers Association in Research Triangle Park, N.C. At more than $100 U.S. per converter, the replacement market exceeds $3.4 billion UI.S. annually. Visteon, a 2000 spinoff of Ford Motor Co., reported $18.3 billion in sales last year and a $352 million loss, as Ford, its largest customer, has cut production. Tenneco, with $3.45 billion in 2002 sales and a $187 million loss, reported a 40 percent decline in third-quarter earnings. All figures in U.S. dollars. Greg Gardner, a spokesman for Dearborn, Mich.-based Visteon, declined to comment on the lawsuit. The company is the world’s No. 4 auto-parts maker after Delphi Corp., Germany’s Robert Bosch GmbH and Japan’s Denso Corp. Since early last year, Tenneco has closed eight factories and fired 945 workers. It sells catalytic converters and other exhaust systems under the Walker brand name. Shares of Visteon were unchanged at $6.54 in New York Stock Exchange composite trading. The shares have lost 3.4 percent of their value in a year. Tenneco shares were unchanged at $5.49 on the New York Stock Exchange. They’ve risen 12 percent in the last year.