The announcement Thursday night by Prince Norodom Ranariddh that he was quitting politics for good led to an emergency session of his party Friday and suddenly altered Cambodia's political landscape.

Prince Ranariddh, who emerged in the 1990s as Hun Sen's chief political rival and only returned to Cambodia on Saturday after a year and a half of exile, told journalists at a dinner party Thursday night he was done with politics.

"I will resign from politics. I will go to work at the Royal Palace, if King [Norodom] Sihamoni allows me to work with him," Prince Ranariddh told a crowded banquet room of reporters. "My resignation will not affect my party."

The prince planned to appoint Norodom Ranariddh Party Vice President Chhim Serkleng as the leader of the party, he said. In an emergency meeting Friday, NRP officials planned to hold an open vote for Chhim Serkleng's leadership role.

Prince Ranariddh left the country in early 2007 ahead of a breech of trust trial, in which he was found guilty in absentia and sentenced to 18 months in prisonfor profiting from the sale of Funcinpec party headquarters when he was its president.

He was granted a royal pardon by King Sihamoni in September, with the approval of Prime Minister Hun Sen.

Prince Ranariddh's resignation announcement was a regretful consequence of political pressure from the ruling Cambodian People's Party, other political leaders said.

"The resignation of Prince Norodom Ranariddh may be from a condition for his return to the country," said Kem Sokha, president of the Human Rights Party. "However, I'm not surprised at his resignation. The prince should have resigned from politics a long time ago, because his popularity has been decreasing."

Government spokesman Khieu Kanharith said Friday the prince's resignation was in the country's interest.

"In the political situation now, we need to compromise with parties for national reconciliation," he said.

Prince Ranariddh's political career began in March 1983, when he formed the Front Uni National pour un Cambodge Indépendant, Neutre, Pacifique, et Coopératif, or Funcinpec, party, contesting national elections in 1993.

Funcinpec won 58 National Assembly seats in the UN-sponsored elections, seven more than the Cambodian People's Party, led by Hun Sen, who denied the results and threatened open war and the declaration of an autonomous zone.

A power-sharing deal ensued, and the two men acted in a co-premiership until 1997, when the CPP seized control of the government following two days of armed conflict in Phnom Penh.

Following a contentious election win in 1998, the CPP offered a coalition deal to Funcinpec, beginning a tradition of political partnership that has lasted until today.

However, Prince Ranariddh split from Funcinpec and opened his own party from exile ahead of local commune elections in 2007 and national elections in July.

Both Funcinpec and the Norodom Ranariddh Party won only two seats apiece in July. The CPP offered the Funcinpec coalition status, but none was forthcoming for the party of the prince.