PTT Plc, Thailand's largest company on the Stock Exchange of Thailand, moved up 14 places on the Fortune Global 500 in the 2013 rankings from 95th place last year.
Chief executive Pailin Chuchottaworn said as the only Thai company on the Fortune Global 500, PTT improved to the 81st spot with total revenue of US$89.945 billion and net profit of $3.37 billion.
"Our continuous improvement over the past few years was due to staff dedication, management capabilities and stakeholder support," he said.
"The achievement also reflects Thailand's ability to build confidence in the eyes of local and international investors," said Mr Pailin.
PTT will continue to help strengthen energy security in Thailand and drive the economy forward, he added.