BEIRUT, Lebanon, March 18 - Political leaders trying to form a new government in the wake of the past month's upheavals said today that negotiations had stalled, raising the possibility that nationwide elections scheduled for this spring might have to be postponed. Allies of the pro-Syrian government and the opposition said the two sides disagreed on a number of important issues, including a demand by opposition leaders for an internationally supervised investigation into the murder of Rafik Hariri, who was killed by a car bomb Feb. 14.Opposition leaders, who have been galvanized by a huge outpouring of public support since Mr. Hariri's death, said they were still waiting for a response to a list of demands they presented two days ago to the caretaker government of Omar Karami. Mr. Karami, leader of the pro-Syrian government, resigned under pressure earlier this month but was asked to return by the Parliament.

By Cynthia Johnston BEIRUT (Reuters) - Syria completed the first phase of its troop pullout from Lebanon on Thursday, bringing Damascus closer to meeting U.S. and Lebanese opposition demands that it quit the neighbor it has dominated for three decades.  A Lebanese security source said 4,000 to 6,000 Syrian troops had returned home since the pullout plan was announced on March 5, leaving 8,000 to 10,000 in eastern Lebanon. He said all Syrian forces had pulled back to the Bekaa Valley or crossed into Syria. "There are just some logistics left. But the people went, all of them," he added United Nations Secretary-General Kofi Annan expects Syria to fully withdraw its forces before Lebanon's May elections, U.N. envoy Terje Roed-Larsen said after briefing Annan on his recent talks with Syrian President Bashar al-Assad.

WASHINGTON (AFP) - US President George W. Bush met with the patriarch of the Maronite church, Nasrallah Sfeir, and reaffirmed that Syria must withdraw its troops and intelligence agents from Lebanon.  "I assured his eminence that United States policy is to work with friends and allies to insist that Syria completely leave Lebanon, Syria take all her troops out of Lebanon, Syria take her intelligence services out of Lebanon, so that the election process will be free and fair," Bush said. The 85-year-old Sfeir, a leading figure in the Lebanese Christian opposition, was making his first visit to Bush's White House even as Syria has begun to pull back its roughly 14,000 soldiers from Lebanon.

WASHINGTON (AFP) - US President George W. Bush left the door open for Hezbollah to play a central political role in Lebanon, urging the Shiite movement to "prove" it does not deserve to be branded a terrorist group.  "We view Hezbollah as a terrorist organization, and I would hope that Hezbollah would prove that they're not, by laying down arms and not threatening peace" between Israel and the Palestinians, said Bush. The White House last week denied a media report that the United States was grudgingly moving into line with efforts by France and the United Nations  to get the group into the Lebanese political mainstream. But aides said privately that Washington faces a quandary how to deal with the group, noting that it wields considerable political clout in Lebanon ahead of May parliamentary elections there.