Shares of Chip Designer Fall After Ruling

Rambus Inc. shares fell 34% after a federal judge said the designer of computer memory chips made some claims that were too broad in a suit asserting that Infineon of Germany violated its patents. Rambus derives most of its revenue from royalties and licensing fees on more than 100 patents. Some analysts have said that a ruling narrowing Rambus’ claims may make it harder to win the case. Judge Robert E. Payne, in the District Court for the Eastern District of Virginia, took a step in that direction Thursday, saying more restrictive technical definitions recommended by Infineon would be used in the trial. Rambus Chief Financial Officer Gary Harmon said the decision may make proving patent infringement a “little more difficult.” Rambus, based in Los Altos, Calif., sued Infineon on Aug. 8 for allegedly infringing four patents that govern how memory chips and supporting semiconductors speed data in electronic devices ranging from personal computers and automated teller machines to telephone equipment. Harmon said Rambus intends to vigorously pursue its claims. The trial was scheduled to begin March 20 but was postponed to April 10. Infineon attorney Charles Armstrong declined to comment. Shares of Rambus fell $8.29 to close at $15.80 on Nasdaq.