(Adds police comment, trader comment)

BANGKOK, June 9 (Reuters) - A fire damaged a diesel-production unit on Monday at the 215,000 barrels-per-day Rayong plant operated by Thai refiner IRPC IRPC.BK , the company's chief executive told Reuters.

The blaze at the refinery, on the coast of the Gulf of Thailand, was brought under control, said IRPC CEO Sukrit Surabotsopon in a telephone interview.

Sukrit was unable to say if output at the plant had been affected.

"The fire broke out at the preparation area to supply feedstock to a diesel cracking unit," he said. "We don't know how much damage there has been. We are assessing it."

A gas leak and explosion caused the fire, which lasted for about 15 minutes, a local police officer told Reuters. Nobody was hurt in the incident, he added.

Thai energy giant PTT is the biggest stakeholder in the plant with a 38.51 percent stake. Other stakeholders include the Government Savings Bank, Bangkok Bank and the Government Pension Fund, according to data from Thailand's stock exchange.

IRPC, formerly Thai Petrochemical Industry, was Thailand's largest corporate debt defaulter after collapsing under a mountain of foreign debt in the 1997/1998 Asian economic crisis.

(Reporting by Pisit Changplayngam and Khettiya Jittapong; Writing by Simon Webb; Editing by Pravin Char)

((Simon.Webb@thomsonreuters.com)(+6626489757)(Reuters Messaging: simon.webb.thomsonreuters.com@reuters.net))

Keywords: THAILAND REFINERY/FIREFIGHTERS