Exxon Mobil reports record profit of nearly $16 billion, but nearly half comes from one-time gains.

NEW YORK (CNNMoney) -- Exxon Mobil reported a quarterly profit of nearly $16 billion Thursday -- the highest ever for a U.S. corporation.

The number beat out the previous quarterly record of $14.83 billion set in the third quarter of 2008, also by Exxon.









But this quarter's massive number includes $7.5 billion from "divestments and tax-related items," partly from the sale of refining and chemical operations in Japan.

Excluding that special credit, the company made $8.4 billion, down 21% from the $10.7 billion Exxon made in the same period last year as falling oil and natural gas prices cut into earnings.

Exxon said its combined production of oil and gas decreased 5.6% from year-earlier levels -- also a worrying trend for investors.

Exxon's quarterly profit of $15.9 billion came on revenues of $127.4 billion, giving it a profit margin of just over 12%.

The company said it paid $26.6 billion in taxes and royalties during the quarter -- $8.5 billion in the form of income taxes.

The lackluster economy caused oil and natural gas prices to sharply decline in the second quarter of this year.

Oil prices were about 9% lower than they were a year ago, while natural gas prices were off about 25%. Exxon produces twice as much natural gas as it does oil.

The falling prices have hit other major oil companies as well.

Earlier Thursday Royal Dutch Shell (RDSA), the world's largest publicly-traded company, reported a 14% drop in earnings. Exxon is the largest U.S.-based company, taking the top spot in this year's Fortune 500 list. It's the world's second largest company based on revenues behind Shell.

Exxon said it spent $9.3 billion searching and developing new oil and gas supplies in the second quarter.

The company touted recent agreements it signed with Russia's Rosneft to develop shale oil deposits in Western Siberia, as well as major expansions at petrochemical plants in Saudi Arabia and along the U.S. Gulf Coast.

But analysts have been critical of Exxon's declining production rates for the last several quarters. Exxon blamed the decline on pre-arranged agreements, OPEC production decisions and the sale of assets.

Some analysts also say the company spends too much money on share buybacks and not enough on dividend payments. Share buybacks reduce the number of outstanding shares, and are intended to boost the company's stock price.

Exxon said it spent $5 billion buying back shares in the second quarter, and noted the dividend increased 21% from the same time last year.

On Wednesday Exxon's board voted to keep the dividend the same going into the third quarter this year, at 57 cents per share.

Shares of Exxon Mobil (XOM, Fortune 500) rose slightly in early trading.