Myanmar named energy giants Chevron, Shell and Total among the winners Wednesday of a landmark auction of offshore oil and gas exploration rights, pinning hope on its natural resources to drive economic growth. The country, left impoverished by nearly five decades of isolation under military rule, has been the subject of feverish interest by energy firms eager to get a share of its untapped energy potential since the removal of most international sanctions in 2012. Myanmar's energy ministry said a total of 68 companies from across the world originally expressed interest in the auction, which was launched in April 2013, with 30 firms eventually submitting proposals. The companies named Wednesday also included US giants Chevron and ConocoPhillips, Norway's Statoil and Britain's BG. A total of 30 offshore blocks were originally up for auction and it is unclear when the remaining 10 sites will be awarded. The ministry said it would receive $226.1 million as a "signature bonus" from the firms once exploration begins on the 10 shallow water and 10 deep water blocks. "This amount is the largest we have received in history" the ministry said in a statement. Despite the excitement over Myanmar's oil and gas potential, there is little data on the extent of the country's reserves. International bidders on the shallow water blocks are required to partner with the local companies, but those taking on the deep water areas are permitted to have full exploration rights due to the high cost and technical skills required. The arrangement is a first in the sector, which was tightly controlled under an opaque and corrupt regime during junta rule. Bidders will, however, be required to enter into a production sharing contract with the state-owned Myanma Oil and Gas Enterprise (MOGE). MOGE has come under fire in the past from opposition leader Aung San Suu Kyi among others for lacking transparency, and the government has pledged openness in an effort to reassure investors over corruption concerns. Several foreign companies have already partnered with local firms in existing offshore blocks, including Total and Chevron who entered before sanctions were imposed.