By Nicole Friedman 

U.S. oil prices recovered from intraday losses Wednesday to end nearly flat, as the market continued to look oversupplied.

Oil futures have plunged for months as global supplies have increased and demand growth has failed to keep up. Brent, the global oil benchmark, is down more than 25% from its mid-June high.

On Wednesday, the U.S. benchmark fell as low as $80.01 a barrel on the New York Mercantile Exchange after U.S. retail sales data was released.

The contract rebounded and wavered between gains and losses Wednesday before settling down 6 cents, or 0.1%, at $81.78 a barrel on the New York Mercantile Exchange, the lowest level since June 28, 2012.

"People are definitely concerned about both the supply and demand side of the equation," said Adam Wise, managing director at John Hancock Financial Services, who helps oversee about $6 billion in oil and gas bond investments. He added that $80 a barrel is an important psychological level.

"Should you see a 7 on the front side of the oil price, I think people would definitely refocus--even more so--their downside scenarios," he said.

However, the market's sharp slide has also prompted some traders who had bet on lower prices to close out their positions, according to market participants.

"Nothing can go down forever without a rally, a short-covering rally," said Donald Morton, senior vice president of Herbert J. Sims & Co. "We could bounce back a bit, but I don't think it's going to change the trend just yet."

Brent, the global benchmark, fell $1.26, or 1.5%, to $83.78 a barrel on ICE Futures Europe, the lowest settlement price since Nov. 23, 2010.

U.S. retail and food sales fell 0.3% in September from August, posting the first monthly decline since January. Economists surveyed by The Wall Street Journal had expected a 0.1% decrease.

Even though gasoline prices were at four-year lows for the time of year, sales at gasoline stations fell 0.8% from August and 2.5% from a year before, indicating that cheaper gasoline didn't spur increased demand from drivers.

The national average for retail gasoline fell to $3.177 a gallon Wednesday, the lowest price since Feb. 22, 2011, according to motor club AAA. One-third of U.S. gas stations are offering pump prices below $3 a gallon, AAA said, compared with less than 4% of stations a year ago.

Traders are concerned that the Organization of the Petroleum Exporting Countries is unlikely to cut output to raise prices. OPEC's next meeting is Nov. 27.

Iran said Tuesday that it is comfortable with current prices, surprising many market watchers. And Saudi Arabia, the largest OPEC producer, has sent mixed signals about whether prices are too low for the country's budgetary needs.

"There was, before, a belief in the implicit support that OPEC would provide," Mr. Wise said. "With sentiment moving away from that, I think people are getting more concerned. You're seeing that reflected in the price."

In the U.S., traders are waiting for weekly inventory data from the Energy Information Administration, which is due to be released Thursday.

Analysts expect the agency to report that oil supplies rose by 2.2 million barrels in the week ended Oct. 10, according to a Wall Street Journal survey. Analysts also expect the report to show that gasoline supplies fell by 1.4 million barrels and distillate stocks fell 1.7 million barrels.

The American Petroleum Institute, an industry group, is scheduled to release its inventory data for the same period later Wednesday.

November reformulated gasoline blendstock, or RBOB, settled down 3.15 cents, or 0.4%, at $2.1487 a gallon, the lowest level since Nov. 23, 2010.

November diesel slipped 1.36 cents, or 0.6%, to $2.4586 a gallon, the lowest settlement since Dec. 10, 2010.

Write to Nicole Friedman at nicole.friedman@wsj.com

Subscribe to WSJ: http://online.wsj.com?mod=djnwires