After negotiating a plea bargain with the U.S. Department of Justice (DoJ) and a $185 million fine last year for its role in a global price-fixing scandal, Hynix was sued Friday in civil court by Sun Microsystems and Unisys.

The companies are seeking unspecified damages for the artificially inflated prices of dynamic random access memory (DRAM) chips, spawned by the conspiracy that has so far ensnared Hynix, Samsung, Infineon and Elpida.

DRAM is the most commonly used semiconductor memory product, providing high-speed storage and retrieval of electronic information for personal computers, laptops, workstations, servers, printers, hard disk drives, personal digital assistants and other computerized gadgets.

A Unisys spokesman confirmed to internetnews.com that the company joined with Sun to bring the lawsuit but declined further comment. At press time, neither Sun nor Hynix returned requests for comment.

The DoJ launched an investigation into price fixing by the world's DRAM makers in 2004.

German chipmaker Infineon was the first to settle with the DoJ, agreeing to a guilty plea and a $160 million fine.

Hynix followed with its plea and $185 million settlement, the third largest criminal antitrust fine in U.S. history.

Months later, Samsung also pleaded guilty and agreed to a $300 million fine for its role in the conspiracy.

Three Samsung executives were also sentenced to U.S. jail terms of seven-eight months and fined $250,000 each.

Earlier this year, Japanese DRAM maker Elpida joined the parade, forking over an $84 million fine.