Tohoku Electric Power Co., the nation's third-biggest user of thermal coal, plans to increase imports from the U.S. and Canada to cut costs and to reduce its reliance on Australian supplies.

The Sendai-based utility will nearly double North American coal purchases to 5 percent of its total, according to Takayoshi Enomoto, the group manager of the company's fuel department. Tohoku Electric is considering shipments from "several promising" projects in the U.S. and Canada, he said in an interview on Dec. 20.

"Even as Australia has established a permanent position as a main supplier, we regret we have been heavily depending on it," Enomoto said at Tohoku Electric's headquarters in Sendai. Boosting coal imports from North America may improve its bargaining power and prompt Aussie sellers to reduce their prices, he said.

The government is urging utilities to pay less for coal, natural gas and oil amid an industrywide reversion to thermal power prompted by the Fukushima disaster. Japan imports almost all of its coal needs and has more than doubled purchases from the U.S., where a shale boom is spurring buyers to switch to gas, clipping coal demand.

The U.S. shipped almost 1.7 million tons of thermal coal to Japan in the first 11 months of 2013, up from 634,000 tons a year earlier, according to data from the Finance Ministry. That was about 1.7 percent of total imports. Canada was the fourth-largest supplier, accounting for 2.3 percent, while Australia shipped 73 percent.