Rambus, who is suing multiple memory manufacturers for SDRAM-related technologies trying to get fees for every RAM chip sold, has lost a patent related to certain memory technologies in Europe.

European Patent Office (EPO) last week made a ruling at the close of a three day hearing revoking Rambus’ European patent 0 525 068 which related to one aspect of Rambus’s patented technologies, a technology called “an access time register.” The patent, for the technology was granted to Rambus on the basis of an application filed in 1991. It covered Germany, France, the UK and Italy, Out-Law.com web-site notes.

Opposition to the patent was filed in 2000; but in September 2002 the EPO affirmed the novelty and inventiveness of the patent, rejecting numerous “prior art” arguments raised by the rival major semiconductor manufacturers. However, the EPO also said that the patent filing would only be valid with further amendment by Rambus to conform more closely to the language as originally filed. This last aspect of the ruling, which reversed a prior EPO decision, was appealed by Rambus. On Thursday, after a three-day hearing, the Technical Board of Appeal of the EPO announced that the patent had been revoked, Out-Law.com reports.

“Although disappointing, today’s ruling by the EPO is a small part of a larger picture,” said John Danforth, senior vice president and general counsel for Rambus.

“We look forward to seeing the EPO Appeals Board written decision when it is available. In addition, of course, we look forward to further progress with respect to our unaffected US patents, some of which are set for infringement trials in US Courts in May and November of this year, Danforth added.

Following normal practice, the basis for the ruling was not given. A written opinion would typically be expected in four to ten weeks. The ruling announced does not apply to other European Rambus or US patents and patent applications that cover other technologies that derive from Rambus’ original Farmwald/Horowitz patent filings, according to Rambus.

However, Micron Technology representatives already celebrate victory by claiming that a number of law-suits against Boise, Idaho-based memory maker initiated by Rambus in Europe will now be terminated. Additionally, officials for Micron said, a number of other Rambus’ patents may be revoked too.