Japan's Komeito party will leave the ruling coalition led by the Liberal Democratic Party (LDP), public broadcaster NHK reported on Friday, in a historic shift for the alliance that has ruled Japan for all but three years since 1999.

Komeito's exit could jeopardize the path for newly elected LDP chief Sanae Takaichi to become Japan's next prime minister, as her appointment would require parliamentary backing from the coalition partner.

Komeito leader Tetsuo Saito informed Takaichi of Komeito's decision to end their 26-year partnership at a meeting on Friday, NHK reported.

It is unclear whether Komeito would continue to support the LDP in parliament, a move that may hurt Takaichi's chances of winning approval for her premiership in a vote expected later this month.

LDP currently has 296 of 713 parliamentary seats for both lower and upper houses, and Komeito holds 45 seats.

The centre-right coalition has been Japan's ruling government to date except for 2009-2012 when the Democratic Party was in power.

Takaichi's selection as LDP leader last week has dampened market expectations for a near-term interest rate hike, sending stocks higher and weakening the yen. She is known for her staunch support of former prime minister Shinzo Abe's "Abenomics" stimulus policies.

Komeito's departure could trigger an unwinding of the so-called "Takaichi trade," which had been driven by investor optimism around fiscal stimulus. (Reuters)