Thein Sein, the acting prime minister, said the final round will discuss elections, political parties, emergency provisions and procedures for constitutional amendments.
"This session is the last session," he said.
1988: Military crackdown on pro-democracy protests, estimated 3,000 killed
1989: Aung San Suu Kyi sentenced to house arrest for allegedly endangering the state
1990: NLD wins landslide in national election; military refuses to recognise result
1991: Suu Kyi awarded Nobel Peace Prize
1995: Suu Kyi freed, but movements restricted
1997: Myanmar admitted to Asean
2000: Suu Kyi sentenced to house arrest for defying travel restrictions
2002: Suu Kyi released following UN-facilitated secret talks with government
2003: Government unveils "road map" to democracy; Suu Kyi returned to house arrest after her convoy is attacked in north of country
2005: Government announces shift to new capital Naypidaw
2007: Nearly 3,000 prisoners released in amnesty to mark independence anniversary, but no key political figures freed
The talks resumed without the country's leading opposition party, the National League for Democracy (NLD).
Despite the boycott, the NLD led by Aung San Suu Ky has submitted proposals for a new charter but received no response.
Thein Nyunt, a party spokesman, said they have been sending proposals to the authorities and the public.
"We are keeping an eye on the convention and deciding what we should do. We will release our opinion on the constitution when the time comes," he said.
In May, the military extended Suu Kyi's detention for another year.
She has spent nearly 12 of the past 17 years under some form of detention.
Without Suu Kyi's participation, western governments and other critics say the talks are nothing more than a smokescreen for the military to seal its grip on power.
A key objective of the convention was to ensure a "leadership role" for the army in politics, reserving key cabinet positions and 25 per cent of the seats in a future parliament for serving military officers.
Brad Adams, Asia director of Human Rights Watch, said in a statement the generals "have trumpeted the convention as a vehicle for a return to civilian rule and the rule of law".
"But they have engineered the outcome to ensure the military remains in control and excluded the people of Burma from the process," he added.
The military, which has ruled Myanmar since 1962, started the on-off convention process in early 1993 but never committed to a timetable to complete the exercise.