The ruling coalition proposed to the opposition camp Friday that the special Diet session convening next Wednesday last 42 days, lawmakers said.
The ruling Liberal Democratic Party and its coalition partner, New Komeito, suggested holding the session from Sept. 21 to Nov. 1.
The opposition parties did not respond immediately.
The ruling and opposition parties plan to meet again Tuesday in a bid to reach an agreement on the length of the special session, they said.
In Friday's meeting, the government presented to the parties its plans to submit 22 bills, including six to privatize Japan Post, the centerpiece of Prime Minister Junichiro Koizumi's reforms.
Other bills include a revision to a special counterterrorism law that would extend the Maritime Self-Defense Force's mission in the Indian Ocean.