CALGARY - Shaw Communications announced this morning that it intends to purchase control of CanWest Global Communications.The Calgary-based cable company has entered into agreements with Canwest and certain 8% senior subordinated noteholders to acquire a minimum 20% equity interest and 80% voting interest in the broadcaster, which includes effective control of a restructured Canwest. Shaw's initial equity interest will exceed 20% depending on the number of Canwest creditors that elect cash rather than shares in restructured Canwest, says the press release.Full financial terms were not disclosed."We are excited about the Investment and gaining effective control of one of the premier...