UPDATE 1-Thai PTT Q4 net misses forecast, 2009 up 15 pct

* Q4 net profit 15.2 bln baht vs 15.8 bln consensus

* 2009 revenue down 20.7 pct to 1.59 trillion baht

* Analysts upbeat on 2010 on strong oil prices

* Shares underperform on concerns over Map Ta Phut (Adds details)

By Khettiya Jittapong

BANGKOK, Feb 19 (Reuters) - Thailand's PTT Plc PTT.BK, the Asia-Pacific's No.3 listed oil and gas firm by market value, returned to the black with a weaker-than-expected fourth quarter profit as higher gas sales outweighed weak refining margins.

Major oil companies such as Exxon Mobil (XOM.N) and Chevron (CVX.N) reported weaker earnings in the October-December period as global refining margins were squeezed with new supplies not matched by demand due to the global recession.

Analysts are upbeat on PTT's 2010 earnings outlook, which is line with the overall sector that oil and gas producers should benefit from crude prices, which should remain strong this year.

"Going forward, we expect improvement in all of PTT's businesses," said Kim Eng Securities analyst Kitichan Sirisukacha adding PTT's gas sales volume should rise 10 percent this year, excluding output from its suspended sixth gas separation plant.

PTT's stock price should face pressure from the slow progress on resolving an environmental row that led to suspension of 64 operations at Thailand's largest industrial estate, Map Ta Phut, including PTT's gas plant.

PTT, which ranks behind PetroChina (0857.HK) (601857.SS) and Sinopec (0386.HK), posted a net profit of 15.2 billion baht ($458 million) on Friday versus a loss of 22.2 billion baht a year earlier, its first loss since listing.

Its earnings were 3.8 percent lower an average forecast of 15.8 billion baht by nine analysts polled by Reuters.

PTT, Thailand's biggest listed company with a market value of about $19 billion, said 2009 net profit was up 15 percent at 59.5 billion baht, from 51.7 billion a year earlier.

The company runs the country's gas pipeline monopoly and controls more than 30 petroleum, gas exploration, petrochemical and refinery businesses.

Fourth quarter sales rose 39.6 percent to 451 billion baht, while petrochemical and refinery subsidiaries contributed profit of 3.04 billion baht, versus a loss of 24 billion a year earlier.

Natural gas sales volume is expected to rise 15 percent from a year earlier to 3.68 billion cubic feet per day in the fourth quarter while PTT group's gross refining margin is estimated at $1.2 barrel a day, down from $5.9 a year earlier.

Thai Oil TOP.BK, the country's top refiner and nearly half-owned by PTT, reported a net profit in the fourth quarter, turning around from a huge loss a year earlier [ID:nBAK002992]

PTT shares have fallen 6 percent in the fourth quarter, while the broader market .SETI has gained 2.4 percent. They closed up 2.75 percent on Friday ahead of the earnings announcement. ($1=33.15 Baht) (Editing by Valerie Lee)