MONTREAL—A public hearing into Bell's $3.4-billion acquisition of Astral Media will focus on how much of the English-language TV market the telecom giant will corner if the deal were to go through.

The CRTC will examine the multibillion dollar transaction on Monday and hear from multimedia, telecom and radio companies, producers as well as film groups and consumer advocates—many of them against the deal.

"The big question is what percentage of the viewing market will Bell end up with after this transaction is concluded," said telecom consultant Mark Goldberg.

"That's the fundamental issue to be explored," said Goldberg, of Toronto-area Mark Goldberg & Associates Inc.

Bell's parent company BCE said if the deal is approved it will own 33.5 per cent of the English-language market, under the 35 per cent threshold set by the Canadian Radio-television and Telecommunications Commission for approval.

However, not every one agrees with the math put forward by BCE (TSX:BCE).

Telecom competitor Telus Corp. (TSX:T) believes Bell would have too much control of English-language TV content and leave consumers with fewer choices and higher cable bills.

Telus has argued that the purchase of Montreal-based Astral, along with Bell's part ownership in the Maple Leaf Sports and Entertainment TV assets, and its stake in joint venture assets, such as Teletoon, would give Bell 49.5 per cent share of the English-language television audience.

The "Just Say No To Bell" campaign's website says if the deal is successful, Bell would control 37.6 per cent of TV viewing. It wants the federal government to stop the deal.

"If Ottawa allows this deal to proceed, Bell Canada will dominate the Canadian TV broadcasting scene and become a threat to the industry and to Canadian consumers," the Just Say No to Bell website says.

"When too much power is concentrated in one company it often means higher prices and poorer choices for consumers."

Goldberg said Bell's English language market share will have to be determined.

"So one of the most contentious issues is figuring out the actual calculation and reaching an agreement there and what approach the CRTC will use," Goldberg said.

BCE announced the Astral deal last March aimed at creating a media powerhouse poised to take on rivals in providing digital content to consumers. At the time of the deal, BCE chief executive George Cope had said the deal gives Bell important new content for online services and mobile devices like smartphones and tablet computers.

In 2010, BCE bought the rest of the CTV assets it didn't already own for $1.3 billion.

CTV operates more than 25 stations across the country, 30 specialty channels including sports networks TSN and RDS online video programming and properties such as CTV.ca, TSN.ca, RDS.ca, MuchMusic.com, MTV.ca and TheComedyNetwork.ca. It also owns CHUM Radio, which operates more than 30 radio stations throughout Canada.

Astral is Canada's largest pay and specialty TV broadcaster and owns 84 radio stations in 50 Canadian markets and 24 television services. It is also the third-largest outdoor advertising company and has a stake in the country's only subscription radio service, XM-Sirius Canada.

If the deal goes ahead, Bell said it would control 24.4 per cent of the French-language market. Bell has said the acquisition of the Astral media assets will provide more competition in Quebec's French-language market which is dominated by Quebecor Inc.