Girija Prasad Koirala took the oath in front of King Gyanendra before legislators met to act on demands from hundreds of thousands of protesters to end the monarch's sweeping powers.

The two political foes stood face-to-face during the short ceremony at the pink-hued Narayanhiti Royal Palace as veteran democracy campaigner Koirala, 84, read out the oath.

He now faces the task of keeping together an unwieldy seven-party coalition and persuading the Maoists to end their decade-long rebellion that has left more than 12,500 dead.

Koirala told the newly convened House of Representatives he wants the rebels to improve upon last week's declaration of a three-month ceasefire.

"Maoists have already declared a ceasefire. I request them to renounce violence and come to the process of dialogue," he said to applause from legislators.

He did not make a direct reference to the rebels' key demand, for a body to draw up a new constitution, which would limit Gyanendra's powers.

But Koirala said he would stay committed to an agreement signed between the Maoists and the opposition alliance that includes a review of the king's powers.

Parliament sat Friday for the first time in four years but Koirala missed it, along with his planned swearing-in ceremony that day, because of bronchitis. He says he is well enough to lead the country.

Koirala, who has been premier several times before, appeared frail but stood to read the oath without any assistance during Sunday's short ceremony, before he was guided by Gyanendra to a seat.

Gyanendra sacked the government and seized total power in February 2005, accusing the administration of corruption and saying it had done too little to tackle the Maoist insurgency.

But the Maoists and a seven-party opposition alliance joined together to mobilise hundreds of thousands on the streets during April in protests, which were often violently suppressed.

One man died in a New Delhi hospital Saturday from injuries sustained during a protest in Kathmandu nine days earlier, bringing the total killed in the 19 days of clashes to at least 16.

Last week, Gyanendra buckled under the nationwide protests and agreed in a televised address to reinstate parliament dissolved in 2002, after earlier asking the opposition to name a premier.

Maoist rebel forces announced a three-month ceasefire Thursday to "motivate" political leaders to call elections to a constituent assembly -- their key demand for joining mainstream political life.

The Maoists, who control large parts of the countryside, are seen as key to any long term solution to Nepal's problems.

There was no immediate word from them after Friday's short first sitting of parliament. The deputy speaker said that legislators would on Sunday discuss plans for elections to a new body to redraft the 1990 constitution.

The current constitution gives the king powers to dismiss the government and take control of the 90,000-strong military.

Banners at rallies have warned politicians that they are being closely watched to ensure there is no repeat of the king's power grab.

But analysts have warned of months of continued wrangling and potential instability because of the complex constitutional issues. The king's future role remains unclear.