In addition to the environmentalists, politicians, and scientists who will gather next week in Johannesburg, South Africa, for the World Summit on Sustainable Development, another constituency will be amply represented — business interests. Many high-profile companies plan to use the summit to burnish their environmental images and make the case that principles and profits can mix. Although some environmentalists believes a number of companies are genuinely committed to cleaning up their acts, others say Big Business is hijacking the summit to push its own agenda: self-regulation and voluntary corporate responsibility over government regulation. Companies like Shell Oil, which is expected to have a large presence at the summit, argue that self-policing ultimately works better than mandatory guidelines, but most enviros disagree. “It needs to be up to much more than the whim of a chief executive as to whether corporations engage in sustainable development,” said Matt Phillips of Friends of the Earth International.