Exxon Mobil Corp. (XOM), the world's largest public oil company, on Thursday said quarterly profit jumped 44 percent on rising oil prices, but the results fell short of Wall Street expectations.

Net income in the first quarter rose to $7.86 billion, or $1.22 a share, from $5.44 billion, or 83 cents a share, in the year earlier period.

Excluding a gain from the sale of a stake in Chinese oil refiner Sinopec (search), Exxon reported profit of $1.15 per share, below expectations of $1.20 per share calculated by Reuters Estimates.

Exxon shares inched down in pre-market trading.

Revenue in the quarter rose 21 percent from year earlier to $82.05 billion, but sales were down from the fourth quarter of last year — snapping a string of seven straight quarters of sequential revenue growth for the oil company. Exxon posted $83.4 billion in revenue in the 2004 fourth-quarter.

Awash in cash thanks to record energy prices, the Irving, Texas company said it would buy back $3.5 billion in stock in the second quarter, up from $2.5 billion in the first quarter.

Basking in the surge in oil prices this year, Exxon's exploration and production operations posted record earnings of $5.05 billion, up 26 percent from a year earlier.

But oil and gas production in the first quarter fell 5 percent from a year earlier, hurt by declining output in mature oilfields and production stoppages. Excluding divestment and entitlement effects, production was down 2 percent.

The energy sector has enjoyed an unusually rosy environment in recent months, as sharp spikes in crude oil prices and soaring refining margins send profits skyrocketing and leave companies flush with cash.

But pulling up production has remained a challenge, as the large Western oil majors face mature oilfields in traditional exploration areas like the Gulf of Mexico (search) and limited access to oil-rich regions like the Middle East and Russia.

Profit at Exxon's refining and marketing operations rose to $1.14 billion, helped by better U.S. refining margins but partly offset by weaker marketing conditions.

Chemical earnings leaped to a record $1.28 billion.

The company's shares fell $2.38, or 4.08 percent, to close at $56 on the New York Stock Exchange.