YAMOUSSOUKRO, Ivory Coast (AP) _ Liberian rebel leader Charles Taylor agreed Thursday to surrender territory held by his fighters to a West African intervention force, a breakthrough in peace plans for the war-ravaged nation.

Elections will be held in Liberia in six months under an agreement reached after an all-night summit of West African and Liberian leaders in the Ivorian town of Yamoussoukro. It was signed by heads of state and representatives of 11 West African governments, by Taylor and by Amos Sawyer, leader of a West African-backed interim government in Monrovia, the Liberian capital.

Taylor invaded Liberia from the Ivory Coast on Dec. 24, 1989. In September 1990, a rival leader killed President Samuel Doe and fighting ensued among the rebel groups. A few weeks later the West African force sailed to Liberia, taking control of Monrovia but leaving Taylor's men holding the countryside.

Under the agreement signed Thursday, the 7,000-man force from seven West African countries will occupy the country and supervise the disarmament of all warring factions within 60 days.

But on major stumbling block remained.

Prince Johnson, the rebel leader who killed Doe, remains camped out near Monrovia and has declared he will not be bound by the agreement because he was not invited to the talks.

More than 13,000 civilians have died in the bloody civil conflict. Some 800,000 Liberians, a third of the population, have been forced to seek refuge in nearby countries.

The indiscriminate killings, widespread looting and burning of villages that terrorized Liberians ended months ago, but the country remained divided and paralyzed because of Taylor's long refusal to disarm his forces.