Canwest News Service: A ruling by Britain’s advertising regulator against oil giant Shell has prompted a new World Wildlife Fund campaign denouncing the petroleum company’s “greenwash” tactics in promoting its Canadian oilsands projects. The U.K. Advertising Standards Authority ruled Wednesday in favour of a complaint by the WWF’s British arm that a newspaper ad in which Dutch-based Shell described its Alberta oilsands operations as “sustainable” was “misleading” and violated ad industry codes for …