(Reuters) – Exxon Mobil Corp and Chevron Corp on Friday reported lower profits due largely to weakness in their refining operations and lower crude oil and natural gas prices.

FILE PHOTO: Gas flares from an ExxonMobil oil refinery in Singapore, February 26, 2019. REUTERS/Edgar Su

Both U.S. oil majors reported increased production, but cited lower refining and chemicals margins, and Exxon posted the first loss in its refining business since 2009. Exxon’s 49 percent fall in first-quarter profit missed forecasts, showing the turnaround at the largest U.S. oil producer remains a work in progress.

“It was a tough market environment for us this quarter,” Exxon Senior Vice President Jack Williams said on a call with analysts.

Wall Street is focused on Chevron and smaller rival