TAIPEI (Reuters) - Protesters occupying Taiwan's Parliament for the last three weeks to block a trade pact with China said on Sunday they will consider leaving now the government has announced a key concession.

Concerned that the deal would increase China's economic influence and hurt local business, the protesters paralysed the legislature to halt the pact's ratification, in the island's worst political crisis in years.

Speaker Wang Jin-pyng said on Sunday that Parliament would now approve a "review mechanism" of trade agreements before the Chinese pact is passed - something the protesters hope will give Taiwan the ability to temper Beijing's clout.

"We strongly support the decision of Speaker Wang to agree to enact the supervisory mechanism before further (parliamentary) review of the trade pact," the protesters said in a statement. A spokesman for the protesters, who asked not to be identified, told Reuters: "Right now we are deliberating whether to vacate the legislature."

The trade services agreement would open 64 of Taiwan's service sectors to China and 80 of China's sectors to Taiwan, a deal Taipei has touted as a way to preserve Taiwan's competitiveness and create jobs.

Opponents fear the pact could hurt local industry and allow potential political meddling by the mainland.

Taiwan's President Ma Ying-jeou had previously expressed openness to a supervisory mechanism for future deals, but maintained that the trade pact be passed in its current form.

The President's office could not be reached for comment.