Japan plans to nominate Kuniji Shibahara, a professor of law at Gakushuin University, to serve as a judge at a United Nations-assisted tribunal to be set up in Cambodia to bring leaders of the Khmer Rouge regime to justice, government sources said Friday.

The sources said that Shibahara, who concurrently serves as a professor emeritus at the University of Tokyo, will almost certainly be chosen by the U.N. as one of the tribunal's nine non-Cambodian judges, given the fact that Japan has played a key role in peace and development of the war-torn Southeast Asian country.

Shibahara has already agreed informally to run for the post, the sources said. If selected as a judge at the Khmer Rouge genocide tribunal, the professor will become the fourth Japanese to serve as a judge at an international court.

Japan's nomination of Shibahara is part of its strong drive for boosting its international prestige by making greater "intellectual," as well as financial, contributions to global peace, the sources said.

At present, Shigeru Oda serves as a judge at the International Court of Justice in The Hague and Soji Yamamoto at the International Tribunal for the Law of Sea in Hamburg, Germany. Chikako Taya, a veteran female public prosecutor, was also elected by the U.N. in mid-June as an "ad litem," or nonstanding, judge at the International Criminal Tribunal for the former Yugoslavia in the Hague.

The U.N.-assisted tribunal in Cambodia will try leaders of the notorious Khmer Rouge regime for such offenses as genocide, crimes against humanity and war crimes. The communist regime is blamed for the deaths of about 1.7 million Cambodians due to disease, overwork, starvation and execution during its rule from 1975 through 1979.

The regime's leader, Pol Pot, died in 1998, but most of his deputies -- including Nuon Chea, the regime's No. 2 man and chief ideologue; Ieng Sary, foreign minister; and Khieu Samphan, who was the nominal head of state -- still live freely in the country.

No one has been brought to justice for the atrocities.

Only two senior Khmer Rouge leaders are in custody: military leader Ta Mok and Kaing Khek Iev, better known as Duch, the director of the Khmer Rouge torture center in Phnom Penh.

In August, Cambodian King Norodom Sihanouk signed a law authorizing the establishment of the Khmer Rouge genocide tribunal following the law's approval in the country's bicameral parliament.

Foreign prosecutors as well as judges will participate in the trial of Khmer Rouge leaders. The trial will be made at three stages -- at a first court, an appeals court and a final court.

Of the 21 judges, 12 will be Cambodians.

The first court will have five judges, including two foreigners, the appeals court seven judges, including three foreigners, and the final court nine judges, including four foreigners. Although Cambodian judges make up a majority of each court, any ruling must be supported by at least one foreign judge.

Before the Khmer Rouge tribunal is actually set up, the Cambodian government of Prime Minister Hun Sen and the U.N. must sign a memorandum of understanding concerning the legal status of non-Cambodian judges and other things. After signing the memorandum of understanding, the U.N. will choose the foreign judges through consultations with the Cambodian government.

Prime Minister Hun Sen has said it is possible that the tribunal will be established by the end of this year. But it is still uncertain exactly when the tribunal will be set up because of the apparent lack of progress in negotiations between his government and the U.N. on the memorandum of understanding.

It is also uncertain whether all of the Khmer Rouge leaders will actually be prosecuted.

Japan, the United States, Russia, Britain and France -- four of the U.N. Security Council's five permanent members -- Australia and other nations have expressed a readiness to send judges to the Khmer Rouge genocide tribunal.

It remains unclear whether China, the fifth permanent U.N. Security Council member and a staunch backer of the Khmer Rouge, will get behind the trial.