Alghabass Ag Intallah, a senior member of the Tuareg-led Ansar Dine group said he had created a new organisation – the Islamic Movement of Azawad (MIA), and was ready to seek a negotiated solution to Mali's conflict.
A French-led military operation is underway in Mali to drive back the Islamist fighters who launched a surprise push southward toward the capital Bamako two weeks ago.
An African ground force is being deployed to support French and Malian troops.
"We want to wage our war and not that of AQIM," said Ag Intallah, referring to al Qaeda's North Africa wing.
"There has to be a ceasefire so there can be talks. The aim is to speak about the situation in the north."
He said the new group, which would be based in Kidal, had been in touch with mediators in Burkina Faso and Algerian authorities. He said rebel demands would be for a broad autonomy rather than independence for the north.
Ag Intallah claimed some members of the Tuareg separatist MNLA movement, which has fought AQIM in the north, had also joined his group.