Shares of refiner IRPC Pcl gained as much as 2.7 percent, hitting a one-month high, as the prospect of higher gross refining margins and petrochemical spreads lifted optimism about its earnings for the second half, brokers said.

At the mid-session break of 0530 GMT, IRPC shares were up 0.53 percent at 3.78 baht, an increase of 5.6 percent so far in the July-September quarter. They fell 23.5 percent in the previous quarter as declining oil prices weighed on earnings.

Broker Phillip Securities rated the stock 'buy', with a target price of 4.9 baht. It expected IRPC to report a net loss of 2.6 billion baht in the April-June quarter compared with a net profit of 2.98 billion baht for the same quarter last year.

"We expect earnings performance in the second half to pick up on the back of a pick-up of gross refining margin on higher diesel demand from Indonesia and stock of finished oil staying at low level," it said in a report.

"If global oil prices stand around this level, petrochemical spread is expected to stay elevated for a while," it said.

Four out of 11 analysts tracking the company rated the stock a 'strong buy' or 'buy', four put a 'hold' and three had a 'strong sell' or 'sell'.

1257 (0557 GMT)

(Reporting by Viparat Jantraprap in Bangkok; viparat.jantraprapaweth@thomsonreuters.com)