Japanese refiner Fuji Oil Co Ltd booked on Thursday a net loss of 29.06 billion yen ($273 million) for the year that ended on March 31, as the month's slump in oil prices caused an appraisal loss of 20.3 billion yen in inventories.

It outstripped the company's February forecast for a loss of 1 billion yen and was the biggest loss since the year that ended in March 2009, a spokesman said.

"The bigger-than-expected loss reflected a hefty appraisal loss and deteriorated margins due to a plunge in oil prices," he said, adding that lower margins cut profit by 8.9 billion yen from the February prediction.

The refiner's run rate fell to 85.4% in the year just ended from 95.8% a year earlier due to a short maintenance period and some glitches afterwards, the spokesman added, but declined to give the planned utilisation rate for this year.

The company did not provide its earnings forecast for the year to next March, saying it was unable to make a rational prediction.

In March, JXTG Holdings, Japan's biggest oil refiner, warned of a record annual net loss of 300 billion yen ($2.8 billion) as plunging oil prices cut its inventory value and the coronavirus outbreak hit demand for oil products.

(Reporting by Yuka Obayashi; Editing by Clarence Fernandez)