Gasoline prices remained nearly flat in the last two weeks after a surge in the cost of crude oil slowed dropping pump prices, the Lundberg Survey (search) said Sunday.

The weighted national average price for all three grades of gasoline dipped about a penny between June 25 and Friday — to $1.96 per gallon, said Trilby Lundberg (search), who publishes the semimonthly aurvey. The survey polls nearly 8,000 gas stations across the United States.

Since May 21, that represents a drop of 14 cents, when the average price was pegged at slightly above $2.10 a gallon.

The biggest seller in the two-week period, self-serve regular, averaged $1.93 a gallon.

In a statement, Lundberg said a steady drop in pump prices leveled off after crude oil jumped about $2 a barrel during the two-week period, spurred by security concerns, Lundberg said.

However, with the Organization of Petroleum Exporting Countries (search) adding 500,000 barrels a day to its output in August — and U.S. refineries maximizing production and imports to meet traditional summer demand — pump prices should remain stable or fall further, Lundberg said.

The national weighted average price of a gallon of gasoline at self-serve pumps on Friday, including taxes, was about $2.03 for midgrade and $2.12 for premium, Lundberg said.