By Jeff St.Onge

July 13 (Bloomberg) -- SanDisk Corp., the world's largest maker of flash-memory cards, sued smaller rival Imation Corp. claiming infringement of patented data-storage technology.

SanDisk said Imation infringed a 10-year-old patent for its Flash EEprom memory system. The complaint, filed July 11, also named Imation's recently acquired Memorex Products unit, which was party to an earlier lawsuit over the same patent.

Milpitas, California-based SanDisk asked the federal court in San Francisco to permanently block Imation from using the technology and to award cash compensation for past infringement.

``SanDisk has been and will continue to be injured in its business and property rights, and is entitled to recover damages for such injuries,'' the company said in court papers.

SanDisk and Ritek Corp. last month settled a dispute over the same patent and agreed to license each other's technology. Terms of the agreements weren't disclosed. SanDisk sued Taiwan-based Ritek and two distributors, Memorex International and Pretec Electronics Corp., over the patent in 2001.

Imation, the Oakdale, Minnesota-based maker of data-storage disks and tapes, purchased Memorex last year for $330 million. It is buying TDK's recording media business and the brand name this year for $300 million, a move that will boost revenue.

``We're evaluating our position and their filing,'' said Brad Allen, an Imation spokesman in a telephone interview. He said the company is ``fully indemnified by our suppliers'' and has its own ``intellectual property in this area.''

Flash memory stores data whether a device is powered on or off and is used in digital cameras, personal digital assistants and MP3 players. They are typically used for temporary storage of data in personal computers, which require constant power.

Shares of SanDisk rose 30 cents to $48.94 in Nasdaq Stock Market trading. They have gained 14 percent this year. Shares of Imation rose 2 cents to $34.76 on the New York Stock Exchange

The case is SanDisk Corp. v. Imation Corp., 07cv3588, U.S. District Court for the Northern District of California (San Francisco).

Last Updated: July 13, 2007 12:43 EDT