The plan was signed in Laiza, capital of the northern state of Kachin, where fighting in recent days between Kachin rebels and army soldiers has triggered a rise in the displaced population.
The Kachin Independence Organisation, whose military arm is the Kachin Liberation Army, has expressed its willingness to sign the accord.
Two years of intermittent combat pitting the Kachin guerrillas and government troops have displaced 100,000 people, more than half of whom have taken refuge in areas controlled by the rebel organisation, according to the UN.
Armed ethnic minority groups, especially the 20,000-strong United Wa State Army, control border areas and lucrative businesses such as casinos, teak wood, jade, gems and, in some cases, heroin and methamphetamine trafficking.
Myanmar, controlled for nearly a half century by military rulers, has embarked on reforms aimed at achieving peace and democracy since the last junta dissolved and handed over power in 2011 to a civilian government made up mainly of ex-generals from the previous regime.
In May, the government signed a ceasefire agreement with the Kachin guerrillas aimed at ending an armed conflict dating back to mid-2011, although each side accuses the other of breaking the truce.
Nearly all of Myanmar's ethnic minorities - including the Shan, Karen, Rakhine, Mon, Chin, Kayah and Kachin, which together account for more than 30 percent of the country's 53 million inhabitants - list greater autonomy as their principal demand.