Prime Minister Junichiro Koizumi and New Conservative Party leader Toshihiro Nikai signed an agreement Monday stating that all seven of the NCP's Diet members will be absorbed by the Liberal Democratic Party.
The merger will allow the LDP to regain a single-party majority in the 480-seat House of Representatives, with 244 lawmakers.
The NCP, the smaller of the LDP's two coalition partners, will formally disband Nov. 21.