Retail gasoline demand fell last week versus a year earlier, as prices dropped for a second straight week but stayed above 2010 levels, a report by MasterCard Advisors' SpendingPulse showed on Tuesday.

Average weekly gasoline demand fell 2 percent in the week to May 20 compared with the same period a year ago, the report said.

Demand fell 1.4 percent compared with the previous week.

Retail gasoline prices dipped 5 cents to an average $3.92 a gallon last week, but were 38.5 percent higher than a year earlier, MasterCard said.

The U.S. Energy Information Administration (EIA) said on Monday prices fell 11.1 cents a gallon to $3.85 a gallon last week after cheaper RBOB gasoline futures contracts on the New York Mercantile Exchange (NYMEX) saved drivers money at the pump.

Prices were about 38 percent higher than the same period last year, according to EIA estimates.

Over the latest four weeks, average U.S. gasoline consumption fell 1.6 percent from year-earlier levels, the ninth straight drop.

(Graphic on four-week average demand:

MasterCard Advisors, a unit of MasterCard Inc, 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 Dale Hudson)