The panel left intact the regulations' disclosure requirements -- designed to show Internet entities are being treated fairly -- but threw out the anti-discrimination and anti-blocking rules, designed to ensure fair treatment of Internet entities.
The regulations were promulgated in 2010 by the Federal Communications Commission. The U.S. Court of Appeals for the D.C. Circuit hears challenges to agency regulations, in this case brought by Verizon.
A densely written 63-page opinion by U.S. Circuit Judge David Tatel said broadband providers are not strictly "common carriers" under federal telecommunications law, which was used to underpin the regulations.
"Given that the commission has chosen to classify broadband providers in a manner that exempts them from treatment as common carriers, the Communications Act expressly prohibits the commission from nonetheless regulating them as such," Tatel said.
"Because the commission has failed to establish that the anti-discrimination and anti-blocking rules do not impose per se common carrier obligations, we vacate those portions of the Open Internet Order."
In part, the regulations were designed to ensure "edge providers," such as Amazon, Google, Netflix or YouTube, are treated equally and fairly by broadband providers, who might be tempted to prioritize access to harm potential rivals.
There was no immediate word on whether the FCC will ask the entire U.S. court of appeals to rehear the case, or ask the U.S. Supreme Court for review.
Net neutrality supporters criticized the decision, saying it could open the way for ISPs like Verizon to compromise Web access.
"[T]he biggest broadband providers will race to turn the open and vibrant Web into something that looks like cable TV," Craig Aaron, president of the advocacy group Free Press, said in a statement. "They'll establish fast lanes for the few giant companies that can afford to pay exorbitant tolls and reserve the slow lanes for everyone else."
Verizon, for its part, said the court's ruling "will not change consumers' ability to access and use the Internet as they do now."
"The court's decision will allow more room for innovation, and consumers will have more choices to determine for themselves how they access and experience the Internet," the company said.