The price of a barrel of oil slipped back on Wednesday after data from the U.S. government showed another increase in gasoline supplies.

On the New York Mercantile Exchange, the price of light sweet crude for August delivery tumbled $2.79 to close at $60.14 US per barrel.

The slide came after the U.S. Department of Energy reported a 1.9 million barrel increase in gasoline supplies last week, which included the Fourth of July holiday, normally a busy driving period. The increase marked the seventh consecutive week that gasoline in storage has risen.

Analysts had been looking for an increase of 900,000 barrels in gasoline inventories.

Also helping to weaken the price of oil was a report from the Organization of Petroleum Exporting Countries that predicted it could take another four years to return oil demand back to 2008 levels.

"So far there is no clear evidence [of] oil demand returning," said energy analyst Victor Shum of the firm Purvin & Gertz.

The reports and the price came one day after the U.S. agency that regulates commodities trading said it will hold hearings on whether to limit the number of energy futures contracts, or bets on the future price of products like natural gas, crude oil and gasoline.

The announcement from the Commodity Futures Trading Commission follows complaints last year that the oil price spike — it hit a peak of $145 US a barrel in July 2008 — was driven by speculative trading.