The coalition said the charter did not reflect the results of negotiations with the military, which seized power last month. The final plan reversed a pledge to have a civilian or military president for 18 months.
Mali's popular opposition movement on Sunday said it had rejected a political charter for an 18-month transition government, backed by the ruling junta.
"M5-RFP distances itself from the resulting document which does not reflect the views and decisions of the Malian people," said the coalition in a statement.
The military junta, which ousted President Ibrahim Boubacar Keita in a coup d'etat on August 18, had backed a charter that outlined an 18-month transition government on Saturday.
The military's support followed three days of negotiations with political parties and society representatives.
Dispute over interim president
One of the discrepancies between the negotiations and charter was the majority pressure for a civilian interim president.
The negotiations agreed that the candidate would be a civilian, but when published, the charter said it could be a civilian or a soldier.
"The desire to grab and confiscate power for the benefit of the CNSP does not justify the means," said the coalition's statement, referring to what the junta calls itself as the National Committee for the Salvation of the People (CNSP).
The June 5 Movement (M5) which took part in the talks said the discussions took place in an environment of "intimidation, antidemocratic and unfair practices worthy of another era."
The coalition includes opposition groups, religious leaders and civil figures who organized months of protests against the former president.
The 15-nation West African regional bloc known as ECOWAS has warned that by Tuesday the junta must designate a civilian leader to head a one-year transition period or else the country could face
ECOWAS has already stopped financial transfers into the country and has closed its borders with Mali.
Junta leader Colonel Assimi Goita said he hoped for support from foreign nations after military leaders agreed to reduce the length of the transition period to 18 months after initially suggesting a three-year period.
International powers have been concerned that ongoing instability will undermine the fight against Islamist militants in West Africa's Sahel region.
kbd/mm (AP, AFP, Reuters)