Tokyo has previously shown interest in joining the Trans-Pacific Partnership (TPP) but remained non-committal in the face of fierce opposition from its cosseted farming industry.

Participation by the world's third largest economy would give a shot in the arm to a pact seen as a key plank of US President Barack Obama's pivot to Asia, and a counterbalance to China's rising regional clout.

Referring to the possibility of joining the TPP, Abe's Liberal Democratic Party (LDP) and its junior coalition partner New Komeito "will pursue the best path that would serve Japan's national interest", they said in their final coalition agreement, the Asahi Shimbun daily reported.

The coalition, that is due to take office officially on Wednesday, also agreed on promoting other free trade frameworks, it said.

The comment contains a more positive note on participation in the TPP compared with the LDP and New Komeito's election pledges before the December 16 poll that brought Abe a landslide parliamentary victory.

In an apparent move to garner farmers' votes, the LDP had said during the election campaign it "opposes participation as long as joining the pact requires preconditions of abolishing tariffs without exception".

New Komeito had also shown a cautious stance on early participation in the trade pact.

The day after Abe's poll victory, Japan's major business lobby Keidanren (Japan Business Federation) urged Abe to join the trade talks "at an early date".

"We urge the new government to participate in the negotiations of the TPP at an early date, as we have no time to waste on the issue," Keidanren chairman Hiromasa Yonekura said in a statement.

Business lobbies say Japan's export-oriented economy is a major beneficiary of the promotion of a global multilateral free-trade system.