IRPC Plc, The operator of Southeast Asia's biggest integrated petrochemical complex, plans to invest $1.2 billion over the next five years, including $135 million this year, senior executive vice-president Atikom Terbsiri said yesterday.

The money would be used to improve refining and petrochemical projects and expand production capacity at a styrene monomer plant in Rayong, he said.

CEO Pailin Chuchottaworn said the run rate of its 215,000 barrel-per-day refinery would rise to 75% this year from 70% last year.

The increased output would mainly reflect plans to use more feedstock for petrochemical plants that are expected to run at full capacity this year, he added.

IRPC, which has no maintenance shutdown plans in 2010, expects sales this year to rise 15% from about 180 billion baht estimated in 2009 because of rising oil prices, Mr Pailin said.

Average oil prices were expected to be about $80 a barrel this year, up from $60 last year, he said.

IRPC shares closed yesterday on the Stock Exchange of Thailand at 4.36 baht, unchanged, in trade worth 172.8 million baht.