Talks with 18 rebel groups hosted in Chiang Mai, Thailand reached a standstill after the Myanmar government refused to extend the ceasefire to three factions fighting in the Kokang border area.
The Myanmar Times reported that 10 of the 18 armed groups refused to sign the ceasefire agreement, calling it "a final decision."
The talks were a central initiative of Myanmar President Thein Sein's administration, and had been going for the past four years.
The collapse makes it unlikely that his Union Solidarity and Development Party will be able to wrap up the agreement before general elections in November.