External Affairs Minister Pranab Mukherjee also underlined that 'redoubled and sustained' efforts are required to develop new, alternative and renewable sources of energy like nuclear and solar at an affordable cost.

Inaugurating a conference of petroleum ministers of several countries here, he said, "bulk of oil and gas potential of the Indian basins still remains locked up".

He said the India Hydrocarbon Vision-2025 lays down the framework for strengthening the hydrocarbon sector, with petroleum and natural gas being at the forefront for this.

The policy has triggered a more definitive paradigm shift toward free market and competition, with increasing private sector and overseas participation in all important segments of the country's hydrocarbon sector, Mukherjee said.

"Ever more areas and opportunities for investment, technology and entrepreneurship are now open for the global players as well as for India's own public and private sectors," the minister told the conclave.