Japan National Oil Corp. on Thursday approved the closure of five of its oil and gas resource exploration companies that are either insolvent or unprofitable.

Most of the 6.31 billion yen the state-run investment firm spent on the five companies' oil projects is expected to be lost, the company said.

The five firms have already ceased operations, it said.

The corporation said Teikoku Oil (Falkland Islands) Co., established in October 1996 and owned equally by itself and Teikoku Oil Co. of Japan, found few oil and gas deposits off the Falkland Islands, a British territory in the southern Atlantic.

Inpex Offshore Bunyu Ltd., set up in June 1997 and owned equally by the corporation and Indonesia Petroleum Ltd., a Japanese firm, found fewer deposits than expected in its exploration area off Kalimantan, an Indonesian territory in the southern part of Borneo.

The operation was known to be high-risk.

Japan National Oil was founded in 1967 by the government to invest in oil and gas projects.

Idemitsu Naoetsuoki Oil Exploration Co. and Teikoku Oil (Offshore Naoetsu) Co., both established in November 1997 to search for oil and gas reserves off the coast of Naoetsu, Niigata Prefecture, were found to be unfeasible, although some gas deposits were detected in tests, it said.

The former was owned 60 percent by the corporation and 40 percent by Japanese petroleum firm Idemitsu Kosan Co., while the latter was owned 60 percent by the corporation and 40 percent by Teikoku Oil.

Inpex Rabe Timor Sea Ltd., established in May 1997, found few oil and gas deposits off Western Timor in Indonesia, the corporation said. It was owned 50 percent by the corporation, 47 percent by Indonesia Petroleum and 3 percent by Japanese trader Nissho Iwai Corp.