Weakened demand for gasoline and increased competition between fuel retailers is reportedly eating into the refiner’s profits, according to the news source.

Reuters also reported Nippon Oil’s chairman as saying that high oil prices may lead the refiner to increase wholesale prices, leading to an increase of retail fuel prices.

Nippon Oil refines approximately a quarter of Japan’s crude oil imports. The Japanese group has a refining capacity of around 1.22 million barrels of oil per day, reported Reuters.