WASHINGTON, DC — According to an Associated Press report late Thursday, Federal Communications Commission Chairman Kevin J. Martin has concluded Comcast misbehaved when it throttled the bandwidth of heavy internet users.Martin told the AP he will recommend sanctions that may include ordering the internet service provider to stop all traffic blocking, reveal how and how often it interfered with data transfers and inform consumers about its methods for managing traffic on its network.

If the FCC follows Martin’s recommendations, the agency’s action will represent the first time an ISP has been punished for violating the FCC’s “open access” regulations. The regulations embody a primary principle of Net neutrality: All traffic is equal, and ISPs must not interfere with it in order to promote their own services or harm services provided by others.

Net neutrality advocates like Free Press, which lodged the original FCC complaint against Comcast, have been hoping for just such a ruling.

“The FCC now appears ready to take action on behalf of consumers,” Free Press said in a statement released Thursday night. “This is an historic test for whether the law will protect the open internet. If the commission decisively rules against Comcast, it will be a remarkable victory for organized people over organized money.”

The Comcast controversy came to light last fall following an AP report that Comcast — the second-largest ISP in the U.S. — appeared to be blocking file transfers that used the popular application BitTorrent. BitTorrent sometimes is used for illegal file-sharing on the Web.

Comcast admitted it was slowing or delaying file transfers of heavy bandwidth users, but the company said it was entitled to manage the traffic on its network in order to ensure sufficient bandwidth for all of its customers. It subsequently agreed to work with BitTorrent and other file-transfer-protocol developers to explore more efficient and less disruptive ways of handling bandwidth hogs.

Comcast is not the only ISP that manages network traffic by throttling the bandwidth of super-users. A German study released in May indicated Cox Communications, the fourth-largest ISP in the U.S., also employs the practice. Among major ISPs, only one other in the world was judged guilty of the practice by the study: Singapore’s dominant ISP, StarHub. The German study found no evidence of traffic interference among phone-based ISPs.

One method of network management currently being tested by Comcast and Time Warner Cable, the third-largest ISP in the U.S., is a tiered pricing model that would charge consumers based upon how much data they transfer each month. An FTC sanction against Comcast may hasten interest in that approach by ISPs across the spectrum, analysts have said.