Max Burt, the former D'Arcy planning director, Loz Simpson, an ex-head of copy at CDP, and Jonathon Hall, previously Ogilvy & Mather's new-business director, claim their venture is a response to the growing emphasis on ethical corporate behaviour.
Their agency will be called Eighty Twenty, reflecting the founders' intention to spend 80 per cent of their time working for fee-paying clients and 20 per cent working free of charge on communication tasks for a variety of non-profit-making bodies.
Twenty per cent of the agency's profits will be distributed to charities chosen by the agency and its clients.
Any client working with the agency must have proven ethical credentials.
The agency insists it will not work with tobacco manufacturers, environmentally unfriendly energy companies or producers of goods targeted at children.
Clients with a history of unethical behaviour will not be welcome and the agency promises to fire clients guilty of corporate misbehaviour.
The shop begins life with a blank client list. But Simpson, who devised the concept, said: "The time is right for an agency like this. Companies are increasingly interested in corporate responsibility and behaving in the correct way."
He added: "For many years, there's been a part of me that's wanted to go to help in the Third World. But I've got four children so it's impossible. This way allows us to match our skills with the desire to give something back to the world."
Burt, who is confined to a wheelchair after a road accident in November 1999, has headed planning on the Government's anti-drink drive campaign and the RSPCA's advertising during a career spanning Abbott Mead Vickers BBDO, Partners BDDH and D'Arcy.
He said: "The accident has made me reappraise life's priorities completely. Much more important now is helping people less fortunate than the majority."