Exxon Mobil Corp.'s (XOM) first-quarter earnings fell 11% on reduced production and sales volumes, as well as higher operating expenses at its exploration and production business.

Shares fell 1.1% to $85.90 in premarket trading as the results missed expectations.

The world's largest publicly traded oil company by market value, which has bet heavily on natural-gas production in recent years, was expected to see profit drop a bit because prices for the commodity had hit decade-low levels.

Exxon Mobil reported a profit of $9.45 billion, or $2 a share, down from $10.65 billion, or $2.14 a share, a year earlier. Revenue increased 8.8% to $124.05 billion.

Analysts polled by Thomson Reuters most recently projected earnings of $2.09 on revenue of $124.76 billion.

Exploration and production earnings fell 10% amid higher operating expenses and as production was down more than 5% on an oil-equivalent basis.

Refining and marketing earnings were up 44% mainly on asset sale gains and improved volume as margins weakened.

During the quarter, Exxon Mobil repurchased 66 million common shares at a cost of $5.7 billion, including $5 billion to reduce shares outstanding.

ConocoPhillips (COP) on Monday reported its first-quarter profit fell 3% as lower production and weaker refining margins offset higher oil prices, in the final quarter before its splits into two companies. Chevron Corp. (CVX) is set to report its first-quarter results Friday.