Alliance Atlantis Communications loudly confirmed what had been quietly known for some time on Dec. 20 when the Toronto-based broadcast giant announced that it is, indeed, on the block and seeking expressions of interest from ‘selected potential buyers.’

The brief statement ended months of discrete inquiries by AAC execs and sounded the starting gun for a bidding war that is expected to reach $2 billion as competitors look to snap up the company’s top-shelf specialty channels – which include the Showcases and History Television – and its 50% interest in the monster CSI franchise.

The most likely suitors are CanWest Global – soon to be flush with cash following the sale of its stake in Australia’s Network Ten – Rogers Communications, Astral Media and Corus Entertainment, all of which have reportedly confirmed some interest in AAC.

‘Certainly it would be an incredible acquisition for CanWest, should they be able to afford it,’ says Hugh Dow, president of the media buying firm M2 Universal, adding it ‘would be an absolute natural with CanWest’s strength in conventional and perhaps their lack of strength in the specialty area.’

CanWest will face increased competition in 2007 if federal regulators approve, as is generally expected, the purchase of CHUM by CTVglobemedia, the newly renamed parent of CTV.

‘If CanWest is going to be in a position to compete, given the pending [CTVglobemedia] situation, they’re going to have to bulk up, and this would be a good way of doing that,’ says Dow.

AAC owns 13 specialty channels and is in the process of selling its 51% stake in Motion Picture Distribution, which went on the market in the fall.

The release noted that AAC’s controlling shareholder, Southhill Strategy – owned by AAC chairman and CEO Michael MacMillan and Atlantis Films cofounder Seaton McLean – has not confirmed its decision to sell its interest in the company.

-With files from Terry Poulton