That would be AllCanada Express (ACE). Contracted to Air Canada Enterprises (ACE). Confusing, eh?
From yyz news,
http://www.yyznews.com/Aug.html
b)...Air Canada Cargo has entered into an agreement with All Canada Express to utilize at least two DC-10s beginning this fall on routes to Europe. These will effectively replace the cargo capacity lost with the withdrawal of the last three Boeing 747-400 combis at the end of October. All Canada Express will operate the flights on a charter basis for Air Canada Cargo, as they currently do with a 727-200 between Toronto and Calgary/Vancouver. More details will be made available when known.
I beleive Air Canada Cargo will sell the space in the bellies of AC airplanes and the space in the AllCanada Express operated 727's and DC10's operated for Air Canada Cargo.