Micron applauded the appeal's court decision. Rambus acted in "bad faith" in the case, said Rod Lewis, Micron's vice president of legal affairs.

"We are pleased that the Federal Circuit panel unanimously agreed ... that Rambus wrongfully destroyed evidence," Lewis said in a statement.

A primary question in both cases is whether Rambus reasonably foresaw litigation when it deleted documents and e-mail messages related to the company's DRAM marketing, patent and litigation strategies back in 1998 and 1999, when the company was looking at ways to get competitors to adopt its DRAM technologies or face lawsuits for patent infringement.

The cases stem from a disagreement over DRAM standards set in the 1990s. Rambus was a member of the standards-setting group the Joint Electron Device Engineering Council (JEDEC) from February 1992 to June 1996, according to court documents.

Rambus had developed and patented technology to improve the performance of DRAM, and the company was concerned that competitors were violating its patents when making their own DRAM products. Rambus attempted to get other companies to license its technology, but the company suffered a setback when Intel, formerly a Rambus customer, announced in October 1998 that it was investing US$500 million in Micron's DRAM efforts.