The average U.S. retail price of gasoline rose slightly over the last two weeks to almost $1.88 a gallon — the first increase reported since late May, according to the nationwide Lundberg survey (search) of about 8,000 gas stations.

But survey editor Trilby Lundberg said prices should resume their slide in coming weeks as increasing oil supplies push fuel prices down.

The national average for self-serve regular unleaded gasoline was nearly $1.88 a gallon in the two weeks surveyed through Friday, Aug. 27, up a half-cent per gallon from the previous survey.

The average price has plunged about 20 cents per gallon since reaching a peak of $2.07 on May 21, according to the latest biweekly survey released Sunday. The average price is 16 cents per gallon higher than it was one year ago.

U.S. crude oil futures prices hit a record $49.40 a barrel on Aug. 20 amid concerns about supply disruptions in producer nations such as Iraq and Russia, pushing gasoline prices higher. That price, just shy of $50 a barrel, was the highest level since oil futures began trading on the New York Mercantile Exchange (search) in 1983.

In the past week, though, some supply concerns eased after Iraq's most revered Shi'ite leader, Ayatollah Ali al-Sistani, persuaded a rebel cleric to accept a peace settlement that ended three weeks of fighting in the holy city of Najaf.

The price of a benchmark U.S. barrel of crude for October delivery fell to settle at $43.18 Friday on the NYMEX.

But Iraq's southern oil exports were still below normal Sunday as firefighters battled to put out a new blaze at a sabotaged pipeline, industry officials said.

"Oil supply has been tight vis-a-vis demand, but now supply has caught up with demand," Lundberg told Reuters.

And while prices crept up in the latest survey, Lundberg expects gasoline will continue to get cheaper.

"I think we will see a resumption of gasoline price cutting," Lundberg said. "Unless there's a true shortage of oil in the world, gasoline prices are likely to decline into and past Labor Day."

At $2.26 per gallon, Honolulu had the highest average price for self-serve regular unleaded gas, the latest Lundberg survey showed. Tulsa, Oklahoma, had the lowest price at $1.72 per gallon.

Trilby said U.S. gasoline inventories currently are "more than sufficient" to meet demand, especially as refineries operate at full capacity.