A US judge has dismissed a complaint brought against Rambus by the US Federal Trade Commission (FTC) that the company tried to unfairly monopolize the memory-chip market.

Judge Stephen J. McGuire, the FTC's chief administrative law judge presiding over the case, dismissed the case in its entirety, ruling that the FTC failed to establish liability for the violations alleged.

The FTC sued Rambus in June 2002, charging the company with violating federal anti-trust laws by engaging in a pattern of anti-competitive acts and practices that served to deceive an industry-wide standard-setting organisation, resulting in adverse effects on competition and consumers.

According to the FTC, Rambus from 1992 to 1995 took part in standards-setting activity regarding SDRAM (synchronous dynamic RAM) technology with the Joint Electron Device Engineering Council Solid State Technology Association (JEDEC), but did not disclose that it had also filed for patents to cover technologies involved in the standard.

Last week, this activity was dealt a blow when the European Patent Office went to the unusual step of revoking one of Rambus patents.

Rambus has said that it complied with JEDEC's rules and that it filed a patent application for its memory technology in 1990, after which it was invited to join the group to develop a related standard. Several chip makers have licensed Rambus' patents, others have challenged the validity of Rambus' patents in court.

The decision to dismiss the complaint is subject to review by the full FTC and by a United States Court of Appeal, Rambus and the FTC said in separate statements.