CBC/Radio Canada won't meet the CRTC's deadline to convert to digital over-the-air television signals from analog by next August, the corporation said Friday.

The public broadcaster said it will require 27 transmitters to make the switchover nationally, but only 15 of them will be active by Aug. 31, 2011, the deadline imposed for major markets by the Canadian Radio-television and Telecommunications Commission.

The remaining 12 will be active by Aug. 31, 2012, CBC/Radio-Canada said.

The Crown corporation has asked the CRTC for permission to continue broadcasting analog signals in those markets until the transmitters are built. The English markets are Yellowknife, Regina, Winnipeg, Windsor, Saint John/Fredericton, Charlottetown, Halifax and St. John's, while the French markets are Vancouver, Edmonton, Regina and Winnipeg.

Even after all 27 transmitters are active, only about 20 of the 30 markets the CRTC has designated as mandatory will be covered, said Steve Guiton, vice-president and chief regulatory officer for CBC/Radio-Canada. Some markets, such as big cities, require two transmitters to cover both English- and French-language services.

"We really couldn't afford to go any further and we cannot do less given the rules and regulations," Guiton said.

CRTC rules require broadcasters to either convert their over-the-air analog signals in markets designated as mandatory by the deadline, or cease airing them completely. CBC/Radio-Canada has also asked the CRTC for an exemption from converting in those extra 10 markets, Guiton said.

CBC/Radio-Canada currently has more than 600 analog transmitters across the country, as well as a handful of digital transmitters in operation in major cities.

Guiton said that once the 27 transmitters — 14 English and 13 French — are up and running, only one per cent of Canadians will have to turn to cable or satellite to continue receiving CBC/Radio-Canada television.

The federal government is resistant to delaying the analog-to-digital transition despite warnings from broadcasters and consumer representatives that the country is ill-prepared for the switch. An estimated 900,000 Canadian households have TVs with antennas that are not equipped to receive digital signals.

U.S. President Barack Obama was forced to delay his country's transition to digital from February to June 2009 when it became clear that industry and consumers were not ready for it.

Washington launched a huge public-awareness campaign and spent more than $1.5 billion US on a coupon scheme to help citizens pay for the new set-top converter boxes they'd need in order to receive digital signals.

Countries around the world are converting away from analog because digital signals use airwaves more efficiently. Many countries have plans to auction off the valuable analog airwaves to wireless companies. The eventual spectrum auction in Canada is expected to raise billions of dollars.