Two junior candidates vying for the presidency of the Democratic Party of Japan agreed Thursday that only one of them should run in the opposition party's upcoming election, sources said.

Seiji Maehara, 40, and Yoshihiko Noda, 45, will meet again later to discuss who should run. The election will be held Sept. 23.

Meanwhile, a third junior hopeful, 53-year-old Takashi Kawamura, decided the same day to drop out because he lacks the endorsement of 20 fellow DPJ lawmakers -- the minimum needed to declare candidacy, sources close to the lawmaker said.

Initially, there were four junior DPJ lawmakers who intended to run: Maehara, Noda, Kawamura and 44-year-old Shigefumi Matsuzawa. The four later agreed to back a single candidate, but their plan fell apart Aug. 20 after they realized they couldn't agree who to field. Two days later, Matsuzawa dropped out, citing his affinity with Noda and the need to consolidate the fractious support base for younger hopefuls, leaving Maehara and Noda.

The front-runners in the election will be 55-year-old DPJ leader Yukio Hatoyama and 55-year-old former party leader and current Secretary General Naoto Kan. Both have declared their candidacies.

Other DPJ members who have expressed an intention to run are former deputy party chief Takahiro Yokomichi, 61, and deputy party chief Kansei Nakano, 61.