DAVID KOENIG, AP Business Writer DALLAS (AP) — Exxon Mobil Corp.’s quarterly profit fell 18 percent from last year, but the Irving-based oil and gas giant still made nearly $8 billion in three months. Production increased slightly, but Exxon made significantly less money at refining. Exxon, the biggest U.S. oil and gas company, said Thursday that third-quarter net income was $7.87 billion, or $1.79 per share. That compared with $9.57 billion, or $2.09 per share, a year earlier. Revenue dipped 2 percent to $112.37 billion. It was Exxon’s second-smallest quarterly profit since mid-2010, beating only this year’s second-quarter earnings of $6.86 billion. Still, the results exceeded expectations. Analysts forecast profit of $1.77 per share on revenue of $107.39 billion, according to a FactSet survey. Earnings at Exxon’s so-called upstream business of finding and drilling for oil and gas improved, rising $740 million to $6.7 billion. Production increased 1.5 percent because of new projects and fewer maintenance interruptions. But profits plunged in the “downstream” business of refining oil and selling the finished products such as gasoline and diesel fuel. That segment earned $592 million, down $2.6 billion from its record third quarter of 2012. Exxon said overcapacity in the refining industry has cut into margins. Profit from making chemicals rose $235 million to more than $1 billion. Exxon has been criticized for slow growth or even declines in oil and gas production. New projects take years to develop. At the same time, oil and gas flows at slower rates in maturing fields. The company has several huge projects in the works, but their payoff isn’t expected until 2015 and beyond. The company increased capital and exploration spending by 15 percent compared with a year earlier. Chairman and CEO Rex Tillerson said Exxon was making progress at tapping opportunities. “We maintain a long-term perspective on our business with a relentless focus on operational excellence and disciplined investing,” Tillerson said in a statement. The company also spent $3 billion buying back 34 million shares during the third quarter, and expects similar spending in the fourth quarter. Shares of the company rose 68 cents to $89.49 in trading before the opening bell. At Wednesday’s closing price, they were up less than 3 percent this year.