(Reuters) - U.S. gasoline demand fell last week even as pump prices fell below levels seen a year ago, MasterCard's weekly SpendingPulse data showed on Tuesday.

Last week's gasoline consumption was 5.6 percent lower than in the same week in 2011. Demand fell by 0.4 percent compared with a week ago, MasterCard data showed.

Meanwhile, prices at the pump fell 6.00 cents to $3.84 a gallon, 1.3 percent lower than a year earlier.

The four-week moving average for demand fell for the 58th straight time, down 5.2 percent from a comparable period a year ago, MasterCard's report showed.

MasterCard Advisors, a unit of MasterCard Inc (MA.N), estimates retail gasoline demand based on aggregate sales in the MasterCard payments system coupled with estimates for other payment forms including cash and checks.

(Reporting by Selam Gebrekidan; Editing by Marguerita Choy)