Key drivers were ongoing growth in PTT's natural-gas business, an 18-per-cent jump the net profit of subsidiary PTT Exploration and Production (PTTEP) and earnings improvements in the petrochemical business.

PTT's refinery business saw weaker earnings, due to lower gross refinery margins (GRMs) in the second half.

However, the lower GRMs were mainly offset by a huge foreign-exchange gain of Bt9.93 billion, due to the baht's strong appreciation against the US dollar.

In last year's fourth quarter, PTT recorded a net profit of Bt15.56 billion, up 68 per cent year on year, as a result of continuous growth in its natural-gas business and an earnings recovery in its petrochemical operations.

The broker expects PTT's net profit to fall 16 per cent this year to Bt79.59 billion, as there will be no repeat of the huge extra gains last year.

PTT last year booked extra gains worth about Bt8 billion from divestment of its stakes in Rayong Refinery, Bangkok Polyethylene and PTT Polyethylene.

The broker estimates normalised earnings to show flat growth this year, as expansion of natural-gas operations helps compensate for a slow-down in refinery earnings, due to softer GRMs.

In addition, Thai Oil - PTT's largest refinery - will shut its CDU-3 unit (capacity of 100,000 barrels per day) for about two months in the final quarter.

Meanwhile, earnings for PTTEP and petrochemicals are projected to show flat growth this year.