Chicago - Exxon Mobil, the world’s biggest energy company by market value, said fourth-quarter profit rose to a five-year high as growing supplies of cheap US oil boosted margins from refining crude into fuels.

Net income increased to $9.95 billion, or $2.20 a share, from $9.45 billion, or $1.97 a share, the Irving, Texas-based company said in a statement today.

Per-share profit was 20 cents higher than the average of 20 analysts’ estimates compiled by Bloomberg.

Profit from processing crude into gasoline, diesel, heating oil and other fuels quadrupled in the quarter compared with a year earlier, as US refinery margins rose 46 percent, in part because of rising oil supplies from shale formations.

Crude futures traded in New York declined by 6.2 percent during the quarter to average $88.23 a barrel, bucking the international trend that saw the global benchmark rise 1 percent to average more than $110.

Oil and gas output from Exxon’s wells fell 5.2 percent to the equivalent of 4.293 million barrels of crude a day from 4.53 million a year earlier, according to the statement.

Crude production, which is six times more valuable than gas on an energy-equivalent basis, fell 2.1 percent to 2.203 million barrels a day from 2.25 million during the year-earlier period.

The company’s so-called upstream unit earned $7.76 billion during the quarter, down from $8.83 billion during the final three months of 2011.

Refining Soars

Exxon refineries earned $1.77 billion during the period, a four-fold increase from $425 million a year earlier.

As the world’s largest refiner, the company processed 4.837 million barrels of crude into fuels a day, down 7.9 percent from 5.25 million during the same period of 2011.

Chemical earnings climbed to $958 million from $543 million, according to the statement.

Exxon agreed in December to pursue the $14 billion Hebron heavy-oil project off Canada’s eastern coast with four partner companies.

The 700 million-barrel oilfield is one of several oil and gas developments from Russia to Australia in which Exxon is investing to boost reserves and halt declining output from wells.

The statement was released before the opening of US stock markets.

Exxon rose 0.8 percent to $90.71 at 8:13 a.m. in New York trading. The company has 12 buy ratings from analysts, 16 hold recommendations and no sell ratings. - Bloomberg