Like all oil firms, Chevron has suffered from the fall in the price of oil

US oil giant Chevron has said that its profits for the first three months of 2009 will be "sharply lower" than those it made in the previous quarter.

The company said that the drop would, in part, be due to falls in the price of crude oil and natural gas.

Chevron made a profit of $4.9bn (£3.3bn) in the final quarter of 2008 but did not say what it will make in the period to the end of March.

The fall in profits will come in spite of an increase in oil production.

Chevron, one of the biggest oil companies in the world, said that margins on refined products fell significantly during the period.

It also said that earnings would include $100m in write-offs associated with exploration.

Chevron increased oil production by 41,000 barrels a day in the US and by 64,000 a day internationally over the first two months of this year.

The company's full results for the first quarter will be announced on 1 May.