Samsung has accused Matsushita's Panasonic subsidiary of violating nine plasma display panel patents it holds, and today filed lawsuits with the US District Court in Los Angeles and Pennsylvania, South Korean news sources report.

Samsung's PDP division, Samsung SDI, said it had held talks with Matsushita on nine separate occasions during the past 12 months, but was unable to negotiate a deal amenable to both parties.

And why did the South Korean company choose to sue a Japanese rival in the US court? “We filed a lawsuit in the US, where there is the greatest demand for digital TVs, because we thought the US, as a third-party would, have no conflict of interest and thus ensure a fair trial," a Samsung spokesman said.

Both firms have a history of display-related litigation. In 2003, Samsung sued Fujitsu, accusing it of infringing its PDP patents. In April 2004, Fujitsu counter-sued, though the two companies eventually settled out of court by signing a cross-licensing agreement.

Matsushita, meanwhile, settled a similar patent clash with LG in April 2005. It sued LG in November 2004, prompting the South Korean firm to counter-sue immediately. ®