SARAJEVO, Bosnia-Herzegovina (AP) _ Bosnian Serbs and the Muslim-led government ended weeks of bickering Monday with an agreement to open a road into Sarajevo for trucks carrying aid. The deal gave new life to a shaky truce.

``It's a very big achievement,'' said Viktor Andreev, the senior U.N. civil affairs officer, who chaired Monday's talks at Sarajevo's airport between rival negotiators.

Though some humanitarian aid comes into the Bosnian capital by another road and through an airlift, reopening the road will considerably ease hardships for the remaining 280,000 residents of Sarajevo, under Serb siege for most of the war.

The agreement foresees the Serb-controlled route opening on Feb. 1.

The two sides also agreed to prisoner exchanges and medical evacuations.

Opening the road was supposed to be part of the four-month truce that went into effect Jan. 1. The road was temporarily opened earlier this month but traffic was halted within hours because of squabbling over who should be allowed to use the route. The Bosnian government wanted it open to everyone, while Serbs sought to restrict it to U.N. and other international aid groups. Under Monday's agreement, all U.N. agencies and five Bosnian humanitarian agencies will be able to use the road, connecting Sarajevo over the airport with government-controlled central Bosnia and the Adriatic Sea via Croatia.

Agreement on its opening was announced by Lt. Gen. Sir Michael Rose shortly before he flew out of Sarajevo at the end of his one-year tenure as U.N. commander in Bosnia.

The task of cementing the cessation of hostilities agreement fell to his successor and fellow Briton, Lt. Gen. Rupert Smith, who commanded British forces in the Persian Gulf War.

Monday's agreement raised hopes somewhat that the truce, now in its fourth week, might outlive its many predecessors and pave the way for resuming peace talks.

The main fighting, which continued Monday, has been in the northwest Bihac region, where rebel Bosnian Muslims and Croatian Serbs who didn't sign the truce have continued to attack government forces.

Andreev said he was confident the agreement would be respected because the Serbs had wrested concessions from the Muslim-led government as part of the deal, including a commitment for prisoner exchanges.

The agreement also allowed for the creation of a joint commission to work out a deal allowing for the freedom of movement for all Sarajevo citizens.

While Serb and government negotiators were meeting in Sarajevo, an American mediator met with Bosnian Serb leader Radovan Karadzic in the Serb stronghold of Pale, just southeast of Sarajevo.

Charles Thomas, U.S. envoy to the five-nation group trying to mediate peace in Bosnia, urged Karadzic to reopen the Sarajevo road and accept the group's peace plan.

Thomas refused to comment after his meeting today, saying only that he had a ``very intensive exchange'' with Karadzic.

Washington has shifted from its policy of no direct talks with the Bosnian Serbs, dispatching diplomats to confer with Karadzic and other rebel Serbs in Pale.

Most of the staff at the U.S. Embassy to Bosnia, including Ambassador Victor Jackovich, reject the new approach and maintain an unwaivering loyalty to the Sarajevo government.

A split between the State Department and Jackovich's embassy, long evident, has widened in recent months. Jackovich is in Washington for consultations, and a U.S. source suggested he was under pressure to give up his post.

The peace plan, accepted by the government in July, would give 51 percent of Bosnia to the government and its Croat allies. Serbs, who now hold 70 percent, would be left with 49 percent.

Serbs repeatedly rejected the plan. Karadzic now says he will use the plan as a basis for talks. But the Bosnian government insists he accept its conditions, and is pressing for a deadline and sanctions.

Rose formally hands off to Smith in Zagreb, Croatia, before the two men travel together Tuesday to Geneva for a meeting with U.N. Secretary-General Boutros Boutros-Ghali.

Responding to criticism he has faced from both sides, Rose said, ``I dispute very strongly'' that the peace process is stalled. ``Most of all, we've seen the guns fall silent, and that to me is a considerable achievement.''

He was immensely popular in Sarajevo last February after he arranged the withdrawal of guns pounding the capital through a NATO ultimatum against the Serbs. But the failure of the United Nations and NATO to halt Serb advances on the Muslim enclaves of Gorazde and Bihac created deep bitterness.

The Bosnian government, accusing him of pro-Serb sentiments, spurned any farewell ceremony.

Rose's modest send-off at Sarajevo airport was a cacophony of horns sounded by U.N. fire trucks and fork lifts.

More than 200,000 people have been killed or are missing in Bosnia's civil war. It began in April 1992, when Serbs rebelled against the republic's vote to secede from Serb-dominated Yugoslavia.