I've always wanted to set up a charitable trust

Robbie Williams

Robbie said of his new venture: "I've always wanted to set up a charitable trust and when the Pepsi deal came along, I thought that would be the perfect kick-start.

"The way I'm asking for more is to ask other people who can afford to give, to do it too."

He is one of the UK entertainment industry's top earners and is estimated to have made �5m last year despite not releasing an album.

The trust will be run by Comic Relief, for whom he has filmed a sketch with Paul Whitehouse, from BBC Television's The Fast Show.

Robbie in full flight for the commercial

The sketch will be screened on Robbie's own website from 1600BST on Saturday.

The Pepsi sponsorship dea,l from which the trust stems, will start in June and is to feature an advertisement in which Robbie makes fun of pop stars who do not sing live.

The singer has already done a considerable amount of work to highlight relief aid undertaken by Unicef, most recently its efforts to combat the effects of flooding in Mozambique.

He also took part last year in a polio vaccination drive in Sri Lanka.