LINCOLN, Neb. -- The Nebraska athletic department has ended its licensing agreement with the father of quarterback Taylor Martinez.

Casey Martinez of Corona, Calif., owns Corn Fed Apparel Inc. His agreement with the athletic department paid Nebraska a 10-percent royalty on Corn Fed T-shirts, caps and other products bearing the Cornhuskers' logo.

Athletic director Tom Osborne said in a statement Wednesday that his staff recently learned that Taylor Martinez is registered as owner of the Corn Fed trademark and the CornFed.com website domain name. Osborne said the quarterback has no ownership in the Corn Fed company and that no NCAA rules have been broken.

Casey Martinez said he initiated conversations about breaking the contract.

"I made the decision to end our agreement to prevent any distractions to my son's time at the University of Nebraska, as well as the football program," he wrote in an e-mail to The Associated Press.

Casey Martinez did not respond to questions about why his son was listed as owner of the trademark and domain name.

Michael Stephens, the assistant athletic director who handles licensing for Nebraska, said last month that the school had taken in less than $500 over the three-year period of the agreement. Casey Martinez said licensed sales make up a small portion of Corn Fed's national sales.

"No monetary gain is worth potential distractions to the football program or our son that may be associated with this agreement," Casey Martinez wrote.

The contract was signed in June 2007 -- one year before Nebraska offered Taylor Martinez a football scholarship. Taylor Martinez signed his letter of intent with the Huskers in February 2009 without visiting another school.

NCAA rules allow parents of a prospective or current student-athlete to enter a business relationship with a school if no special arrangements are made and the business is legitimate.

"Such arrangements, however, could raise concerns and possible scrutiny," NCAA spokesman Erik Christianson told the AP last month.

Casey Martinez said the name Corn Fed was trademarked in 2000 and incorporated in 2004. He began seeking licensing agreements with universities in 2006, and Nebraska was the first to sign on. Iowa, Iowa State and Northern Iowa followed.