Japan's free trade accord with the Association of Southeast Asian Nations was assured of ratification Friday as the country's divided parliament ended its session.
Under the deal, about 90 percent of trade between Asia's largest economy and the 10-nation ASEAN bloc will be tariff-free within 10 years.
The pact was to be automatically ratified at midnight (1500 GMT Friday) as it remained pending in the upper house for 30 days after approval by the more powerful lower house.
The lower house, dominated by the ruling Liberal Democratic Party, voted for the accord on May 22. But legislation has been held up in the opposition-controlled upper house.
The government had extended the parliament session by six days as the ruling coalition wanted to win approval for key bills including the free trade accord with ASEAN.
Under the constitution, international treaties signed by the government are automatically ratified if the upper house does not make a decision within 30 days after approval by the lower house.
All parliamentary business came to an end on Friday although the turbulent session was to formally close on Saturday.
The opposition ramped up pressure on unpopular Prime Minister Yasuo Fukuda by passing a non-binding censure motion against him on June 11 over a controversial medical plan affecting people over 75.
The lower house responded with an approval motion in Fukuda, who has refused to call early elections.
A comprehensive economic partnership agreement, the core of which is the free trade accord, was signed in April by Malaysia, the last of the ASEAN members to sign off on it.
It will be the first multinational free trade agreement for Japan, which also has been seeking to conclude a flurry of bilateral pacts amid a breakdown in global trade negotiations.
Tokyo has reached bilateral deals with eight nations, six of which are in the ASEAN group -- Brunei, Indonesia, Malaysia, the Philippines, Singapore and Thailand. The others are Chile and Mexico.