Korean chip maker Hynix has pleaded guilty to charges of price fixing and will pay a $185m fine, the US Justice Department has disclosed.

The fine is the third largest ever imposed in the US for anti-trust violations.

Hynix conspired with Infineon Technologies of Germany and others to sell chips to certain customers at a fixed cost, affecting the price computer vendors such as Dell, HP, Apple and IBM paid for memory chips.

"This illustrates the international scope of our criminal investigations and underscores the importance of looking beyond our nation's borders to prosecute and deter cartels that harm American consumers," said Hewitt Pate, assistant attorney general for the anti-trust department.

Infineon pleaded guilty in October 2004 to similar charges and paid a $160m fine. Four of the company's executives were sentenced to jail terms of between four and six months and fines of $25,000 each after entering guilty pleas.

In December 2003 the US Justice Department charged an executive at Micron Technology, an American manufacturer of memory chips, who admitted to withholding and altering documents that had been subpoenaed.

The investigation into the price fixing continues, and the Justice Department expects that the agreement with Hynix will provide additional information.

Samsung Electronics has also come under investigation for joining in the cartel, as has Elpida Memory. Hynix and other chip makers also face civil lawsuits from computer vendors.

Suspicions of price fixing arose after memory chips showed a sudden spike in prices in 2001. The rise was unusual because it occurred at a time when PC sales declined and large memory makers had been struggling financially for years.