South Korea's Samsung SDI said it had filed a lawsuit in the United States against Japanese consumer electronics giant Matsushita Electric for patent violation. Samsung SDI said the lawsuit against Matsushita, best known for its Panasonic brand products, had been lodged with US courts in Los Angeles and Pennsylvania.

The legal action came after a year of negotiations failed to resolve a dispute between Samsung SDI and Matsushita over plasma display panel (PDP) technologies.

"We filed a case against Matsushita and Panasonic over their violation of our patents on key PDP manufacturing technology," Samsung SDI said in a statement on Wednesday.

Samsung SDI is the world's largest maker of PDPs, which are flat screens used for thin televisions and other display monitors and are one of the fastest growing segments in the hi-tech market.

The South Korean company accused the Japanese company of infringing on nine of its PDP technology patents.

Last year Samsung SDI reached an out-of-court settlement with its Japanese rival Fujitsu over PDP technologies and agreed to forge ties.

In April, Matsushita settled a PDP patent row with LG Electronics after the South Korean company agreed to pay royalties.