Texas released a statement by Patterson several hours after Orangebloods.com reported, citing two unidentified sources, that Brown will announce he is stepping down by week's end.
"We continue to discuss the future of Texas Football," Patterson said. "Mack Brown has not resigned. And, no decisions have been made."
Joe Jamail, Brown's longtime friend and attorney, told The Associated Press on Tuesday: "Mack Brown has not resigned." He says Brown's future with Texas is still up to the coach.
Horns247.com, a Texas recruiting website, reported that Brown denied the report in a text from Florida, where he was recruiting.
Brown wrote to Horns247: "I have not decided to step down."
Texas just completed another regular season that didn't meet expectations. The Longhorns went 8-4, recovering from a 1-2 start and beating Oklahoma, but still finishing with lopsided late-season losses to Oklahoma State and Baylor.
There has been speculation about Brown's future in Austin since even before the season started, and it became rampant after blowout losses to BYU and Mississippi in September.
Brown fired defensive coordinator Manny Diaz after the BYU loss and replaced him with Greg Robinson. The move seemed to help. The Longhorns played better, and the season peaked with a 36-20 victory against rival Oklahoma in October.
Texas is set to play Oregon in the Alamo Bowl on Dec. 30.
Longtime Texas athletic director DeLoss Dodds announced that he would be stepping down earlier this season, and former Arizona State AD Steve Patterson has already been hired to replace him.
The future of another powerful ally of Brown's could also be decided later this week in Texas.
The University of Texas system Board of Regents is meeting Thursday and they are scheduled to discuss and possibly vote on whether Bill Powers will remain the university president at Texas.
Powers has had a tenuous relationship with the board for several years and is believed to have a slim majority of support among the nine members.
No decision on Brown was expected to come until after Power's future at Texas was decided.
Brown is 158-47 at Texas, including a national championship in 2005 and another BCS title game appearance in 2009. Since that season, the Longhorns are 30-20 and 18-17 in the Big 12.
If the Longhorns job comes open, expect more speculation about Alabama coach Nick Saban replacing him.
The AP reported last month that after last season Texas regents had spoken with Saban's agent about the possibility of replacing Brown and approached Brown about stepping down.
AP College Football Writer Ralph D. Russo contributed to this report.