Furness, Withy & Company Limited v. Minister of National Revenue, 68 DTC 5033, [1968] CTC 35, [1968] SCR 221 -- summary under Article 8

Article 5 of the Canada-U.K. Income Tax Convention of 1946 did not exempt earnings of a U.K.-resident shipping company derived from managing or agency or stevedoring services which it rendered in Canada to other corporations, although it was entitled to exemption respecting amounts which arose from charges made by its Canadian branches for agency and stevedoring services to ships which were owned and chartered by it and were operated in its own shipping service.