Osaka Gas Co. failed to declare 2.39 billion yen in income over a four-year period to March 2003 and was slapped with some 780 million yen in punitive fines by the Osaka Regional Taxation Bureau, sources said Monday.

The city gas supplier reported 45 million yen in pipeline construction costs as a nontaxable expenditure, but the tax authorities judged the company tried to hide its earnings, they said.

A spokesperson for the company said, "Although we had different views over tax payments with the taxation authorities, we have completely followed their order."

The tax bureau also decided the company could not declare renovation costs for its gas-producing plants as expenses, and ordered it to depreciate its property in accordance with the length of time the plants have been in service, saying the costs amounted to capital expenditure, the sources said.