Earlier on Monday, Marathon said it would acquire rival Andeavor for more than $23 billion (17 billion pounds) to form a company that would leapfrog Valero Energy Co as the largest U.S. refiner by capacity.

Marathon's higher profit and its deal for Andeavor both come as U.S. refiners benefit from stronger demand thanks to U.S. shale output hitting record highs.

U.S. refiners, which source heavy crude from Canada, have also benefited from cheaper oil from the region.

Marathon's refining and marketing margins rose 1.3 percent to $1.81 billion in the three months ended March 31.

Net income attributable to Marathon rose to $37 million or 8 cents per share, from $30 million or 6 cents per share a year earlier.

The company, which also operates convenience store chain Speedway, said total revenue jumped 16 percent to $18.98 billion.

(Reporting by Yashaswini Swamynathan in Bengaluru; Editing by Sai Sachin Ravikumar)