Japan and India on Wednesday launched a joint research project into pricing structures in LNG markets, the Japanese government said, amid complaints that energy-hungry Asia is paying above the odds.

Japan is the world's top importer of liquefied natural gas. Asian buyers pay far more than those in North America because the price is index-linked to oil on the continent.

Under the present pricing structures in LNG markets, the price in North America is determined on the basis of supply and demand.

Japan's industry minister Yukio Edano and Montek Singh Ahluwalia, deputy chairman of India's Planning Commission, signed the agreement on joint research in Tokyo.

Resource-poor Japan is on the hunt for cheaper energy, a situation worsened by the shuttering of all but two of its nuclear reactors amid public distrust following tsunami-sparked meltdowns at Fukushima.

India's expanding economy is also hungry for more energy.

LNG is gas that is temporarily liquefied for easier storage and transportation.

The United States has increased its production of shale gas, a natural gas trapped in flakes of sedimentary rock. This has pushed down the price for natural gas in North America and is raising interest around the world.