Thai energy company PTT said it was looking into setting up a subsidiary in Myanmar that would oversee as much as $3 billion worth of investments through 2016.
PTT Chief Operating Officer Nattachat Charuchinda said the time was "ripe" to invest in Myanmar.
"PTT sees Myanmar is rich in natural resources and the group itself has long been familiar with Myanmar's authorities," he was quoted by the Bangkok Post as saying. "We're keen on investing in setting up a 150,000-bpd refinery as well as a petrochemical business in Myanmar."
The announcement comes roughly one week after Washington authorized U.S. investments in Myanmar, which in 2010 began a series of political reforms.
French company Total officials were in Myanmar last month to discuss prospects in the energy sector, prompting concern from U.S. lawmakers that U.S. companies were slow to move into the country.
Total said that, as of 2007, Myanmar was producing around 180,000 barrels of oil equivalent per day, with 90 percent of that represented by natural gas.