The company's Trillium Cable division served several markets in Ontario, including Scarborough, Windsor, Barrie, Pickering, Chatham and Leamington, and was also a minority investor in other smaller cable companies, including Northern Cable in Northern Ontario, UMG Cable in Smiths Falls, Perth, Brockville, Cobourg and Port Hope, and several local systems in The Midlands region of England.
CUC's broadcasting holdings included radio stations CKLW and CKEZ in Windsor, and a 25 per cent founding stake in YTV, which had increased to 34 per cent by the company's dissolution in 1995. Through its share in Northern Cable, it also held a stake in that company's radio and television subsidiary Mid-Canada Communications until its share of that company was bought out by local shareholder Norman Bradley in 1989.
Conway's death in 1988 made the company a strong takeover target, and by 1989 an active struggle for the controlling share of the company was under way. Control was ultimately maintained by Julia Conway, Geoffrey's widow.
CUC sold its radio stations in Windsor to CHUM Limited in 1993. The deal was approved by the Canadian Radio-television and Telecommunications Commission, and formally established the commission's current practice of granting the Windsor market a special exemption from its normal concentration of media ownership rules because the city's proximity to the Metro Detroit market in the United States was threatening the financial viability of Windsor's radio and television services.
CUC was acquired by Shaw Cable in the 1990s, for a purchase price of $645 million. First announced in April 1994, the deal was reached as part of a bidding war which also saw a competing offer from Cogeco. The purchase received CRTC approval in February 1995.
The merger of CUC's 420,000 subscribers with Shaw's, along with an additional 102,000 subscribers added from Shaw's simultaneous purchase of Classicomm, made Shaw the second largest cable company in Canada.
Shortly after the takeover was approved, Shaw cut 251 jobs from Trillium in the engineering, customer service and finance departments, due to operational redundancies with Shaw's existing staff.
Following an exchange transaction between Shaw and Rogers Cable in 2001, most of Trillium's and UMG's former markets are now served by Rogers, with some areas, such as Windsor, Chatham and Leamington, now served by Cogeco Cable.
- "Rivals eye cable empire after founder's death". The Globe and Mail, April 2, 1988.
- "Geoffrey Conway: Cable pioneer sought channel for children". The Globe and Mail, March 1, 1988.
- "Cable takeover kills 251 jobs New owner axes Trillium staffers". Toronto Star, June 15, 1995.
- "Struggle under way to control CUC Broadcasting, sources say". The Globe and Mail, March 2, 1989.
- "Ontario cable firms". The Globe and Mail, May 9, 1984.
- "CUC closer to lining up partner Broadcaster negotiating with Telus for cable-TV venture in Britain". The Globe and Mail, September 23, 1992.
- "Radio rules waived for Windsor". The Globe and Mail, January 30, 1993.
- "Firm that owns CHRO sold; Deal for Northern Cable may halt bid for Ottawa licence". Ottawa Citizen, May 27, 1989.
- "Shaw to cut CUC by 251 jobs Will reduce new unit's work force by almost half over next 4 months". The Globe and Mail, June 15, 1995.
- "Shaw buys Ontario network". Calgary Herald, April 30, 1994.
- "Shaw hooks CUC in $635M deal". Financial Post, April 30, 1994.
- "CRTC approves Shaw purchase". Edmonton Journal, February 18, 1995.
- "Ontario cable deal keeps Shaw in big leagues; Shaw on the move". Edmonton Journal, July 30, 1994.