High oil and natural gas prices pushed ConocoPhillips' first-quarter profits up 17 percent, the Houston-based company said today on Thursday.

The third-largest U.S. oil company said net income climbed to $4.14 billion or $2.62 a share, for the January-March period, from $3.55 billion, or $2.12 a share, in the year-ago quarter. Analysts surveyed by Thomson Financial expected earnings per share of $2.42.

ConocoPhillips said revenue rose to $54.9 billion from $41.3 billion a year ago. Meanwhile, its average global sales price for a barrel of crude in the first quarter was a hefty $92.88, up from $53.38 a year ago.

Crude prices have risen roughly 80 percent since this time last year, nearly hitting a record of $120 a barrel this week.

Although we delivered solid financial results during the first quarter, unplanned downtime negatively impacted our performance, said Chairman and Chief Executive Jim Mulva, adding that the Houston-based company's refineries, like those of many other oil companies, were affected by lower margins.

Daily production in the most-recent quarter averaged 1.79 million barrels of oil equivalent a day, down from 2.02 million barrels a year ago. The company attributed the decline to the expropriation of its Venezuelan oil projects last year and its exit from Dubai, as well as normal field decline and unplanned downtime in the continental U.S.

The surge in crude prices squeezed refining margins to their lowest levels in years, as refiners were unable to offset the rise in crude costs through higher product prices due to weak demand, Oppenheimer & Co. oil analyst Fadel Gheit said in a report this week.

Looking ahead, Mulva said he expects the company to reach its strategic objectives set for the year, as refining margins improve.

He also noted the company will buy back $2 billion to $3 billion in shares in the second quarter.

Occidental Petroleum, the fourth largest U.S. oil and gas company, said it earned $1.85 billion, or $2.23 per share, compared with $1.21 billion, or $1.43 per share, a year earlier. Revenue jumped 50 percent to $6.02 billion.

ConocoPhillips shares fell $1.48, or 1.8 percent, to $83.00 and Occidental Petroleum lost $1.33, or 1.6 percent, to $83.16.

ConocoPhillips' two larger U.S. rivals, Exxon Mobil Corp. and Chevron Corp., are scheduled to report earnings next Thursday and Friday, respectively.