A customer holds a gas pump handle Thursday at an Exxon station in Vancouver, Wash. Exxon Mobil Corp. reported second-quarter earnings of 1.68 billion Thursday, the biggest quarterly profit ever by any U.S. corporation, but the results were well short of Wall Street expectations and its shares fell.

Houston ? Exxon Mobil reported the fattest operating profit in U.S. corporate history Thursday but took a beating anyway – from politicians railing against Big Oil, drivers bleeding cash at the pump and investors who expected more.

The world’s largest publicly traded oil company turned a profit of $11.7 billion for the second quarter, lifted mostly by meteoric crude prices. Its earnings were up 14 percent from a year ago.

Total sales: $138 billion – roughly the gross domestic product of Hungary.

Henry Hubble, Exxon Mobil’s vice president for investor relations, said the record profits “highlight the quality of our integrated business model and disciplined investment approach.”

For the most part, the plaudits ended there.

Despite their heft, Exxon’s profits were a disappointment on Wall Street, and the company’s stock slumped nearly 5 percent. Almost the entire energy industry was walloped by investors Thursday.

European rival Royal Dutch Shell posted its own record profit across the Atlantic, with earnings of $11.6 billion. Its American depository receipts tumbled nearly 4 percent in afternoon trading.

Growing investor apprehension can be found at the heart of what the oil industry does – finding and producing oil and natural gas.

Exxon Mobil’s overall output fell 8 percent in the second quarter from a year ago – a significant blow for a company that generates more than two-thirds of its earnings from oil and gas production.

For Exxon Mobil, which produces 3 percent of the world’s oil, finding new deposits of hydrocarbons is getting harder and harder. State-run oil companies like those in Saudi Arabia and Venezuela control about 80 percent of known global oil reserves.

It’s difficult if not impossible for Exxon and its competitors to get any part of that oil.

“It all comes down to production,” said Brian Youngberg, an analyst with financial services firm Edward Jones. “This is the second straight quarter production came in below expectations. Investors are going to be questioning when they can turn that around.”

Exxon Mobil was not alone in the industry in posting massive profits over the past week.

The reward? A broadening backlash from a public that is getting squeezed on fuel prices from every front.

Unleaded gas cost $3.74 per gallon at a Mobil station in Milwaukee, where Jeff and Jennine Pynn of Putnam Valley, N.Y., stopped Thursday during a 10-day road trip. “It’s totally unfair,” Jennine Pynn said as she pumped $47 worth into a Toyota Highlander. “You really hope to see them not turn so much of a profit.”

Dan Owens of Muskego, Wis., drives about 100 miles a day as a sales representative for a packaging firm. He called Big Oil’s profits “obscene.”

“I’m all for making a profit – it’s the American way. But it’s another thing to gouge,” said Owens, 38, shaking his head. “It makes me feel like I’m getting ripped off.”

While the oil companies insist they’re trying to find new oil that might bring down gas prices, the money they spend on exploration pales compared with what they’ve spent in recent years on stock buybacks and dividends.

In the most recent quarter, Exxon Mobil said it spent $8 billion buying back stock, versus $7 billion on capital and exploration expenditures. The company has said it expects to spend $25 billion to $30 billion on capital and exploration projects each of the next five years.

In a letter to the five largest international oil companies released Thursday, some House and Senate Democrats demanded the companies spend more of their profits on U.S. production and renewable energy and less buying back their own stock.

“Given today’s strong market incentive for expanding exploration and production, we can only believe that reinvesting your vast profits into the production of more oil and natural gas in the United States is a profitable strategy that will help our country decrease its dependence on foreign oil,” said the letter from Sens. Charles Schumer, D-N.Y., and Robert Menendez, D-N.J., and Reps. Rahm Emanuel, D-Ill., and Ed Markey, D-Mass.

The American Petroleum Institute, the industry’s trade association, said Big Oil earnings are not out of line compared with earnings in other industrial sectors.

For example, the institute notes, Exxon’s earnings amount to about 8.5 cents per dollar of sales, versus 11.6 cents for the companies making up the Dow Jones industrials.

“The oil and natural gas industry is massive because it has to be to effectively compete for global energy resources,” said John Felmy, the API’s chief economist. “The industry’s earnings make possible the huge investments necessary to help ensure America’s future energy needs are met.”