Japan may cut its reliance on nuclear power in half through 2030, according to Shigeru Muraki, executive vice president of Tokyo Gas Co.

"In my view, nuclear may account for 15 percent of total power generation in 2030, from about 30 percent before the nuclear disaster," Muraki said in a Wednesday interview in Kuala Lumpur during the World Gas Conference.

Natural gas may account for as much as 30 percent of primary energy sources from 2020 onward, from about 19 percent currently, he added.

Japan has idled all of its nuclear power plants following the March 2011 catastrophe at the Fukushima No. 1 facility. The country is now buying record amounts of gas to make up for the electric generation shortfall.

Imports of liquefied natural gas to Japan, the world's biggest buyer of the fuel, may be limited to 90 million metric tons a year by 2025, compared with 83 million now, because of restrictions on power-generation capacity, Muraki said. The country has increased LNG imports by 10 million tons since the Fukushima crisis started, he said.

Tokyo Gas, the country's largest distributor, is interested in buying LNG from North America, Muraki said.

"We are interested in the shale energy from North America," he said. "The U.S. will be the first, as it has pipeline access, also terminals, and physically U.S. LNG exports will be much faster than Canada."

Muraki said he is not optimistic that every LNG project proposed in the U.S. and Canada will become a reality, though the supply will affect the market.

"Certain volumes that may come out from the U.S., like 20 to 40 million tons, will have a positive impact on LNG trading," he said.