Thailand was supposed to cut exports of natural rubber on April 1 along with Indonesia and Malaysia, the date agreed by the International Tripartite Rubber Council (ITRC), made up of the three countries, back in March.

The three countries account for about 70 percent of the world's natural rubber production and decided for export cutbacks of 240,000 metric tonnes collectively to support prices.

But Thailand, the world's top rubber exporter, delayed the measure because of its general election in March, and will cut exports between May 20 and Sept. 19, the head of the Rubber Authority of Thailand said.

"Thailand will proceed as agreed by the three countries, and will assess results every month," Yium Tavarolit, acting governor of the authority told Reuters.

"If prices don't move, then we have to review the measure."

The step follows an agreement by the ITRC in late 2017 to cut natural rubber exports by 350,000 tonnes for three months.

Besides curbing exports, the group also agreed to try to significantly ramp up the domestic use of rubber in each of the three producers through developments such as rubberised roads.

(Reporting by Panarat Thepgumpanat; writing by Patpicha Tanakasempipat; editing by Christian Schmollinger)