Energy ministers and oil executives from around the world have gathered in Turkmenistan for an oil and gas show.
Correspondents say Western countries, China and Russia are vying for access to the Central Asian state's huge reserves of fossil fuels.
Turkmenistan, which was largely isolated from the outside world for many years, has now said it wants foreign investment.
It currently sells most of its gas to Russia at below market prices.
For almost two decades, until his death last year, President Saparmurat Niyazov ruled the country with isolationist policies so extreme that children were banned from learning foreign languages.
The BBC's Natalia Antelava, in the capital Ashkabad, says most foreign investors never felt welcome during Mr Niyazov's rule.
But the fuel show is the biggest event Turkmenistan has hosted in many years, and is being seen as a test of the its willingness to join the international community.
Our correspondent says hundreds of investors have turned up in the hope that Mr Niyazov's successor, Kurbanguly Berdymukhamedov, is serious about opening up the country's oil and gas industry.
Almost a year on since he first took power, Mr Berdymukhamedov has made it clear he is willing to reform.
His rhetoric was already enough to attract potential investors.
But many of them say they need to see real changes and sign real deals before they agree to stay.