Lady Young's appointment to the four-year post had been widely expected.

A former chief executive of the Royal Society for the Protection of Birds and currently chairperson of English Nature, Lady Young became a peer last year.

Her new duties will begin on 1 August, Downing Street said.

Lady Young, 50, succeeds Lord Cocks of Hartcliffe. She previously served on the BBC's general advisory council.

Though a Labour peer she is not seen as being in UK Prime Minister Tony Blair's inner circle.

At the instigation of the Labour Government the post was advertised openly for the first time, but it became embroiled in accusations of Labour "cronyism".

The film-maker and Labour adviser Lord Puttnam was on the shortlist, as was Gail Rebuck, chairperson of Random House publishing and wife of Blair insider Philip Gould.

Bland to stay until 2003

The BBC chairman Sir Christopher Bland will remain in his post for a further two years after April 2001, Downing Street said.

The decision to extend his original five-year contract was taken in light of the decision of BBC Director General Sir John Birt to retire in 2000.