The ANR is active in eastern Chad, near the border with Sudan and the Central African Republic.

The accord, signed in Gabon, provides for an immediate ceasefire and an amnesty for all ANR fighters and supporters.

Chadian Foreign Minister Mahamat Saleh Annadif said former rebels would be integrated into the national army or be given support to go back to civilian life.

He called on the other rebel groups to join the agreement.

Fighting has resumed in northern Chad despite a peace deal signed last year between the government and the Democratic Movement for Justice in Chad (MDJT).

From the newsroom of the BBC World Service