Samsung Electronics Co. Ltd. (005930.KS) is being investigated by fair trade watchdogs in South Korea, Japan and the United States, the second Korean flat screen maker named in a probe into possible price-fixing, a news agency report said on Tuesday.

The report, from South Korea's Yonhap news agency, follows a disclosure by LG.Philips LCD Co. Ltd. (034220.KS) on Monday that it was the target of an investigation by the Korean Fair Trade Commission (KFTC), the Japanese Fair Trade Commission (JFTC) and had received a subpoena from the U.S. Department of Justice.

Shares in LG.Philips were down 5.56 percent at 25,500 won by 0023 GMT after hitting a record low of 24,950 won, against the wider market's 0.12 percent rise.

LG.Philips (LPL.N), a joint venture between LG Electronics Inc. (066570.KS) and Philips Electronics (PHG.AS), vowed to fully cooperate with authorities.

Yonhap cited unnamed regulatory and industry sources in reporting local antitrust authorities were also looking into possible collusion by Samsung and LG.Philips to fix the prices of LCD products and control their supply.

A KFTC spokesman said he had no knowledge of the investigations. Calls to Samsung Electronics were not immediately returned.

Late on Monday, a KFTC spokesman said the probe was being conducted by the Cartel Investigation Group.

LG.Philips was the world's biggest maker of the large LCD panels used in flat-screen TVs and PC monitors last year. But in 2006, the loss-making company has been overtaken by rival Samsung, which teamed up with Japan's Sony Corp. (6758.T)