The issue echoes broader debate on the merits of what is often called net neutrality, the principle that Internet providers and governments should treat all data on the Internet equally.

It was brought to the fore by public complaints that BCE Inc's (>> BCE Inc.) Bell Mobility unit and Quebecor Inc's (>> Quebecor, Inc.), Videotron unit have given undue preference to their own content. BCE and Quebecor are two of Canada' biggest telecom companies.

"They weren't applying the cost associated with seeing the Bell mobile services, but if you were watching YouTube or another video service it would count against the cap. That's the problem," Jean-Pierre Blais, chairman of the regulator, the Canadian Radio-television and Telecommunications Commission (CRTC), said in a phone interview.

"There is no different treatment between content you control and content you don't control. I don't like the phrase net neutrality, but it is similar to that, there aren't fast lanes and slow lanes," he said.

Several of Canada's big telecom companies have bought broadcasting and other media assets in a trend known as vertical integration, while broadcasters and distributors have also struggled with the emergence of cheaper online alternatives.

The CRTC said Videotron has already pulled its offending product, illico.tv, and that Bell Mobility has until April 29 to abide by the ruling.

BCE said it was shocked by the ruling, which will affect 1.5 million subscribers to its mobile-TV offerings, of which it said only 20 percent were Bell Media content.

"There's a hint here that the government believes Bell Mobile TV delivers only Bell Media content," a spokesman said. "They should know we offer mobile-TV content from all of Canada’s leading broadcasters in English and French."

Quebecor did not respond to a request for comment.

The mobile-TV ruling was one of three that Blais announced on Thursday, but the most widely anticipated decisions to come out of consultations on television held by the CRTC last year won't come until March, he said.

First will come a ruling on financial support for the creation of Canadian TV content, then on whether viewers should be able to pick and pay for only for the cable channels they watch, and finally a policy on consumer empowerment.

(Reporting by Alastair Sharp; Editing by Peter Galloway)

By Alastair Sharp

Stocks treated in this article : BCE Inc., Quebecor, Inc.