The CNDP commanders said they were placing their forces at the disposal of the Congolese army high command "with a view to them being reintegrated into the national army".
The commanders were led by General Bosco Ntaganda, a top CNDP leader who last week broke away from the Tutsi rebel movement's founder, General Laurent Nkunda.
It is unclear whether Nkunda is supporting the ceasefire and subsequent moves to reintegrate fighters within government forces.
Before the CNDP split, rebel fighters had defeated the government army in Congo's eastern province of North Kivu, displacing a quarter of a million civilians and sparking a humanitarian emergency.
Last month, the United Nations' Security Council unanimously voted to renew its peacekeeping mandate in Congo for another year, amid accusations that both government soldiers and rebel fighters had carried out atrocities against civilians.