The appeal is Comcast's latest court challenge to FCC Chairman Kevin Martin. Comcast appealed this year an FCC-imposed cap on Comcast's size. The FCC seeks to limit Comcast's power by saying it cannot control more than 30 percent of the nation's pay-TV market. Comcast's appeal of the cap is pending.

In yesterday's action, the Philadelphia cable giant says the FCC has authority over Internet service providers, but has not enacted "enforceable rules or standards" on Internet-management practices. The appeal was filed in the U.S. Court of Appeals for the District of Columbia Circuit.

Martin said that he was disappointed with Comcast's court challenge and that the company agreed not to block or degrade Internet content when the commission approved its acquisition of the Adelphia cable system several years ago.

Unanswered questions remain with Comcast's treatment of Internet traffic, Martin said in a statement. "The commission needs to understand the answers. Perhaps more importantly, Comcast's subscribers deserve to know the answers," he said.

Last month, the FCC, in a 3-2 vote, ordered Comcast to halt a discriminatory practice of blocking or interrupting certain Internet traffic. It told the company to disclose to the government regulator its Internet-management practices and how it would change those practices in 30 days.

Comcast said that it would follow the FCC order, but that it thought the FCC was making up rules as it went along.

"We intend to make the required filings and disclosures, and we will follow through on our long-standing commitment to transition to protocol-agnostic network-congestion-management practices by the end of this year. We also remain committed to bringing our customers a superior Internet experience," David L. Cohen, Comcast executive vice president, said in a statement.

Comcast's critics said the appeal did not come as a surprise.

"We expected Comcast would appeal the commission's order. The company opposed it every step of the way, even as they failed to disclose their throttling of Internet traffic," Gigi B. Sohn, president and co-founder of Public Knowledge, a nonprofit advocacy group, said in a statement. "We believe the commission will prevail and the rights of Internet users will be protected."