Jan. 23 (Bloomberg) -- Twenty-two supertankers are being used to store crude oil rather than deliver it, as much as 37 percent less than other estimates, London-based E.A. Gibson Shipbrokers Ltd. said.

The carriers have been booked for storage to take advantage of a market structure called contango, where oil futures prices rise as the year progresses. Frontline Ltd., the largest owner of the ships, said Jan. 14 that 30 to 35 very large crude carriers, each able to hold about 2 million barrels of crude, were deployed for the purpose.

Demand for storage may be an “on/off occurrence for some time” because of “uncertainty in world markets,” Gibson said in a report today.

To contact the reporter on this story: Alaric Nightingale in London at Anightingal1@bloomberg.net

Last Updated: January 23, 2009 10:37 EST