ABUJA (Nigeria): Sudan's Government and the largest Darfur rebel group agreed on Friday to sign a peace plan, a top U.S. envoy said, marking major progress in an internationally backed effort to end the death and destruction in western Sudan.

U.S. Deputy Secretary of State Robert Zoellick said two smaller rebel groups that rejected the treaty could be bypassed, and his assessment was bolstered when one of the two split on Friday, with dissenters criticising their leader for not joining the treaty.

``Today the largest group, Minni Minnawi's, has agreed to sign and the Government of Sudan have agreed to sign as well,'' Mr. Zoellick said.

``Not all the movements are in accord, but we're already getting phone calls that people with [rebel faction leader] Abdel Wahid [Nur] believe he has made a mistake.''