UPDATE 1-Thai PTT sees better 2010, $2.5 bln spending

* Higher oil demand, prices to boost 2010 earnings

* To spend $2.5 billion on continuing projects

* Subsidiary PTTEP sees higher Q4 results

* PTTEP's insurance claims to cover damage in Montara (Adds details, outlook of subsidiary PTTEP)

BANGKOK, Nov 12 (Reuters) - PTT Pcl PTT.BK, Thailand's biggest energy firm, on Thursday forecast higher revenue and net profit next year on stronger demand and higher oil prices.

The company planned to spend 82 billion baht ($2.5 billion) next year on investment in continuing natural gas businesses, Chief Executive Prasert Bunsumpun told reporters.

"Results next year will be better than this year, both for profits and revenue. This is because demand for oil is rising and the trend is for oil prices to remain high next year," he said.

Revenue for the first nine months fell 32 percent to 1.14 trillion baht, with net profit for the period dropping 40 percent to 44 billion baht.

Full-year revenue would fall short of last year's 2 trillion baht while 2009 net profit would only match the 51 billion baht of 2008 as it expected small gains in oil inventory, after a huge inventory loss last year due to falling prices, Prasert said.