Some of the world's biggest luxury conglomerates have failed to make the grade in a ranking of ethical and environmental performance.

A report released today by the WWF, the conservation group, entitled "Deeper Luxury", gives Bulgari and Tod's, the Italian jewellery and accessory companies, a grade F for their "environmental, social and governance performance and reputation" in 2006 of the 10 largest publicly traded luxury conglomerates.