Since 2002, the Justice Department has been conducting a probe of alleged DRAM price fixing in the late 1990s and early part of this decade.

Four companies and 12 executives have so far pleaded guilty to participating in the conspiracy and have been assessed more than $730 million in fines.

In May, three of the four companies, Samsung Electronics, Hynix Semiconductor Inc. and Infineon Technologies AG agreed to pay a total of $160 million to settle class action suits related to price fixing. Elpida Memory Inc., the fourth company to plead guilty, is still involved in the class-action suits.

The lawsuits charge that DRAM manufactures maintained a secret agreement to raise prices from about 1998 to sometime in 2002. The suits target Samsung, Hynix and Infineon, as well as Micron Technology Inc., Mosel-Vitelic Corp., Nanya Technology Corp., Elpida Memory Inc. and NEC Electronics America Inc. The suits seek unspecified damages and restitution.

Micron admitted wrongdoing in the federal probe, but received immunity from federal criminal charges in return for cooperating. Justice Department officials have called the conspiracy "one of the largest cartels ever discovered."

According to New York's lawsuit, DRAM manufacturers regularly exchanged price information and other confidential business data in order to raise the prices that OEMs and other DRAM customers paid for memory chips. The suit seeks to recover damages on behalf of consumers and local governments in New York, according to the attorney general's office.

"The defendants in this case conspired to rig the U.S. market for this essential computer product, working together to keep prices artificially high," said Bill Lockyer, attorney general for California. "In the process, they victimized individual consumers, governmental agencies, schools and taxpayers."