Texas may collect $2.6 billion less in taxes over the next two years as the largest U.S. producer of oil's coffers are hit by the downturn in crude prices, state officials said on Oct. 13.

"Despite the significant retrenchment in the oil and gas sector we witnessed in fiscal 2015, revenues remained in line with the estimates we made in January," said Texas Comptroller Glenn Hegar. "That said, we anticipate that prolonged weakness in oil and gas markets will continue to slow our economy."

The state projects the revenue available for spending will fall to $110.4 billion in 2016 and 2017, down from a prior estimate of $113 billion in its previous biennial estimate that projects how much revenue will be available in the next two-year budget cycle.

Texas, which is active in the Permian Basin, Eagle Ford and Haynesville shale plays, collects taxes on the market value of oil and gas production. Since hitting a peak over $100 per barrel 15 months ago, crude prices are down 50%.