May 28 (Bloomberg) -- U.S. gasoline demand fell 5.5 percent last week, a sign record pump prices are prompting drivers to spend less time on the road, MasterCard Inc. said today.

Consumers purchased an average 9.39 million barrels of gasoline a day in the week ended May 23, down from 9.93 million a year earlier, MasterCard, the second-biggest credit-card company, said in its weekly SpendingPulse report. Demand for the motor fuel rose 2.7 percent from the previous week.

The national average pump price for regular gasoline rose 8 cents to $3.84 a gallon, up 19.6 percent from a year earlier and the highest in data going back to October 2006, the report showed. AAA and the U.S. Energy Department also reported record prices in the past week.

Gasoline demand compared with a year earlier has dropped in 15 of the past 18 reports from MasterCard.

The report from Purchase, New York-based MasterCard was assembled by MasterCard Advisors, the company's consulting arm, and is based on credit card swipes and cash and check payments at about 140,000 U.S. gasoline stations.

The Energy Department estimated demand of 9.36 million barrels a day for the week ended May 16. MasterCard said demand was 9.14 million barrels a day for the same period. MasterCard's demand figures have been about 1.7 percent higher, on average, than the Energy Department's over the past year. The government's next petroleum report is set for release tomorrow.

Visa Inc. is the biggest credit card company by transactions processed.

To contact the reporter on this story: Barbara Powell in Dallas at Bpowell4@bloomberg.net.

Last Updated: May 28, 2008 14:01 EDT