Tillman intends to launch the Fashion Enterprise Fund (FEF) this autumn, which will kick off with at least£5 million. The fund will invest in new designers who can provide credible business plans.
The FEF will have support from the Centre for Fashion Enterpise, which has backed designers including Basso & Brooke and Marios Schwab.
Tillman and Shepherdson will interview prospective candidates and be available to offer advice during the early stages of their businesses.
HBoS chairman Lord Stevenson will join Tillman and Shepherdson on the FEF's board. Tillman told the Financial Times: 'The biggest problem for a start-up business is you can't afford good expertise.'
He added: 'First you have to do a lot of research into the people, to make sure they have the ability to be independent business people.'
Profit from the venture will be split between the designer, investors and the London College of Fashion.
Shepherdson has not held any high-profile position since she left Sir Philip Green's Topshop last October.
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