President Buyoya (right) has taken advice and is stepping down

President Pierre Buyoya a Tutsi, threw his departure into doubt last month when he called for a national debate on whether or not he should leave office before the integration of Hutu rebel fighters into the mostly Tutsi army.

It was also reported that he wanted to stay on because of the fragile ceasefire.

The power-sharing deal reached with some rebel groups and political organisations allowed for the change of leader exactly half-way through the transitional three-year government of ethnic Tutsis and moderate Hutus.

The BBC's reporter in Burundi, Prime Ndikumagenge, told the Focus on Africa programme that Mr Buyoya decided he would step down after widespread consultations.

He added that the president decided to go because he said he wanted to respect the constitution and leave as promised.

Tutsi vice president

As part of the deal, mediated by Nelson Mandela, Hutu Vice President Domitien Ndayizeye is due to take over.

A Burundian delegation is now in South Africa to discuss who the new Tutsi vice president should be.

Three out of four rebel groups signed the peace agreement, but the truce has not always been observed.

Last weekend, the rebel group who refused to sign the agreement, the Forces for National Liberation (FNL), ended secret consultative talks in Switzerland with a pledge to hold future meetings.

More than 300,000 people, mainly civilians, have been killed in the nine-year civil war in Burundi.