BANGKOK, Dec 31 - PTT Chemical PCL (PTTC.BK) will defer maintenance at its 461,000 tonnes per year (tpy) ethane cracker by about two months to February, while it holds trial runs at its new 1 million-tpy cracker, its CEO said on Thursday.

The shutdown will be for 45 days.

Everything is going on track with the 1 million-tpy cracker, CEO Veerasak Kositpaisal told Reuters.

Right now, we are in the process of warming up the machineries. Definitely, it will be able to start up in early 2010, he added.

Veerasak was dismissing market talk that PTT Chemical, Thailand's top olefins producer, might not be able to start the new gas unit as planned.

Traders had said PTT Chemical might be short of gas feedstock after Thailand's court suspended 65 new plants at Map Ta Phut, the country's biggest industrial estate, for their owners' failure to conduct health impact assessments, triggering fears of a start-up delay. [ID:nSGE5BS01E]

Among the projects suspended are PTT's sixth gas separation plant and expansion projects of PTT Chemical. [ID:nSGE5BO00G].

Veerasak said the company had been switching feedstock step-by-step from some of its units to be used in the new cracker.

We'll start reducing production capacity of Olefins I-1 (the 461,000 tpy ethane cracker) to bring its gas feedstock to use with this new cracker, he said.

As a result, the 45-day maintenance shutdown at the I-1 will be postponed from late this year to February of 2010.

The change in maintenance plan is due to the events at Map Ta Phut, which affect PTT's new gas separation unit, he said, adding that the matter should be resolved quickly.

The government has agreed last week to back court appeals on 19 projects it deems safe enough to resume operations, while PTT will seek the go-ahead for its nine suspended projects, provided they had received operating licences before the 2007 constitution. [ID:nSGE5BS01E]

PTT Chemical also operates a 400,000-tpy ethane cracker and another 515,000-tpy naphtha cracker at Map Ta Phut, in eastern Rayong province. (Reporting by Pisit Changplayngam; Writing by Seng Li Peng in SINGAPORE; Editing by Ramthan Hussain)