Like global energy companies, Idemitsu has benefited from stronger crude oil prices, which translate into higher prices for refined products and increased inventory values.

Oil prices have hovered above $100 per barrel in the April to June quarter on tight supplies following Western sanctions on Russia, a major producer, and as energy consumption returned to near pre-pandemic levels.

Idemitsu now predicts a net profit of record 280 billion yen ($2.1 billion) for the year to March 31, against its May estimate of 165 billion yen. It also beat a mean forecast of 207 billion yen, according to a Refinitiv poll of nine analysts.

"Surging prices of oil and coal and a weaker yen contributed to strong first-quarter results and an upgrade of our full-year forecast," Yoshitaka Onuma, general manager of the finance department, told a news conference.

Its net profit for the April-to-June first quarter nearly doubled to 245 billion yen.

"Robust petroleum product margins in Singapore also led to higher earnings in exports," Onuma said, adding Idemitsu's export volume is expected to increase 53.5% this year from a year earlier, also helped by higher operation rates at its refineries.

Refinery run rates came to 82% in the first-quarter, above an annual rate of 77% last year.

Idemitsu lifted its annual assumption of Brent oil prices to $105.1 a barrel from its May estimate of $102.5, spot Australian thermal coal prices to $310.1 a tonne from $180, and the yen's exchange rate to 133.6 yen per U.S. dollar from 120 yen.

"The global coal market has tightened as Russian supply has fallen amid the Russia-Ukraine conflict, boosting demand for Australian coal as an alternative," Onuma said, adding soaring prices of natural gas in Europe had also boosted coal demand as substitute.

"We don't think the tight supply situation will change anytime soon," he said.

($1 = 134.8600 yen)

(Reporting by Yuka Obayashi; Editing by Jan Harvey)