Jonathan Ross's BBC deal is worth a reported �6m a year

The review, which will be announced in July, comes after "top talent" pay was leaked, including a three-year-deal for Jonthan Ross worth a reported �18m.

BBC chairman Sir Michael Lyons told a House of Lords committee that the "issue of public concern" would be subject to the trust's "oversight".

But he added that star contracts were the decision of the director general.

Value for money

Sir Michael, who heads the trust, said it would explore whether the BBC has become a "market-maker" in its payments to stars. but added that the corporation operates in a highly competitive market.

The reported Ross deal is said to have influenced multi-million pound contracts struck by ITV to secure Simon Cowell and Ant and Dec.

Sir Michael Lyons said the Trust has to examine talent payments

Further details of the trust's study of the BBC's "major role" in the talent market will be made public when the BBC's annual report is launched on 3 July.

It will have to be concluded by 31 March 2008.

Another report about the BBC's commissioning process will examine whether licence fee payers are getting value for money from the BBC.

Director general Mark Thompson defended top talent salaries in front of a Commons select committee last year, saying that a BBC which did not secure big stars would not please the public.