Tokyo Electric Power Co. (9501.TO) and Tokyo Gas Co. (9531.TO) separately said Monday that they have extended purchases of liquefied natural gas from the Kenai LNG plant in the U.S. state of Alaska by two years to March 31, 2011.

Japan's largest power utility by capacity, also known as Tepco, and Japan's largest gas utility by sales volume declined to specify the respective volumes to be purchased under their extended contracts.

Neither Tepco nor Tokyo Gas have decided on supply sources to succeed the Alaskan LNG for their gas-receiving terminals near Tokyo, company spokesmen said.

Tepco has bought 918,000 metric tons a year of LNG from ConocoPhillips (COP) and Marathon Oil Corp. (MRO), owners of the Kenai LNG plant, since 1969. The contract had expired March 31 this year.

Tokyo Gas has also bought LNG from the two companies since 1969, its spokesman said, without specifying volumes.

-By Mari Iwata, Dow Jones Newswires; 813-6895-7572; mari.iwata@dowjones.com