Senator Mar Roxas, one of the figures behind the Japan-Philippines Economic Partnership Agreement (JPEPA), said the deal was ratified late Wednesday after a marathon session.

"It is timely that we acted on JPEPA at this time," Roxas said in a statement posted on the Senate website.

He said the deal was necessary for the Philippines to remain competitive within Southeast Asia, where other countries have bilateral arrangements with Japan.

The agreement is the Philippines' first bilateral free trade deal and would pave the way for the removal of all tariffs on about 80 percent of Philippine exports to Japan.

Philippine business leaders have said that the treaty could boost exports by up to 1.4 billion dollars annually, as well as lead to tens of thousands of new jobs.

But environmentalists led by Greenpeace have warned that some provisions of the treaty would allow Japan to export its toxic and hazardous waste to the Philippines.

In July, the Supreme Court threw out a suit filed by left-wing lawmakers to force the government to reveal confidential details of the deal.

But Roxas sought to allay public fears on Thursday, saying that the Senate will "maintain a hawk's eye vigilance against any potential abuse by either side."

"This is just the beginning," he said of the agreement's potential benefits. "It is up to our government, in cooperation with the private sector, to fulfil and maximize the gains made possible through this treaty."