Indian Oil Corporation, the country's largest oil refining and marketing company, has submitted an expression of interest to acquire the marketing assets of a mid-size oil company in Thailand.

The move would give IOC access to about 80-90 retail stations in Thailand, with volumes close to half a million tonnes, company executives said.

The IOC board on Thursday cleared the decision. The company is also actively scouting for acquisition possibilities in Singapore and Indonesia, apart from forays planned in Pakistan and Bangladesh.

India's only Fortune 500 company was also assessing medium-sized exploration and production firms in Britain, Canada and Australia, executives said.

The IOC board has also cleared the acquisition of an exploration firm abroad and has built a war chest of $2 billion. This would secure its crude oil supply and help the company become more competitive, government officials said.

IOC plans to invest in the upstream sector as well as in petrochemicals to compete with more diversified rivals.

IOC competes with Reliance Industries, which operates India's largest single refinery at Jamnagar with a capacity of 660,000 barrels per day, has stakes in oil and gas fields and is a dominant petrochemicals maker.

It also competes with the Oil and Natural Gas Corporation, which took a majority stake in Mangalore Refinery and Petrochemicals Ltd last year.

IOC was earlier seeking a stake in ONGC's foreign investment arm, ONGC Videsh Ltd, which has stake in oil and gas fields in several countries including Russia, Sudan, Myanmar and Vietnam.