Idemitsu Kosan Co., Japan's second-largest refiner, and partners including Norsk Hydro ASA have received approval from the Norwegian government to develop a 47 billion yen gas project in the North Sea, the company said Monday.

Idemitsu will invest about 7 billion yen to produce gas and condensate, a type of light-grade crude oil, according to a statement issued by the company in Tokyo. The offshore Vega South Gas field is 135 km northwest of Bergen, Norway.

Japanese oil refiners are expanding their overseas oil and gas businesses to compensate for declining petroleum demand at home. Idemitsu is seeking to boost oil and gas assets abroad through acquisitions, with its oil production in the North Sea totaling about 30,000 barrels a day.

The field will start supplying gas starting October 2010 and is estimated to produce until 2022, with peak output reaching the equivalent of about 28,000 barrels of oil a day, according to the statement.