Coyle, who is married to the BBC's technology correspondent Rory Cellan-Jones, has been selected by culture secretary Jeremy Hunt to work alongside the new BBC Trust chairman, Lord Chris Patten.
Hunt's Department for Culture, Media and Sport confirmed today that Coyle's proposed appointment has been put forward to the Privy Council for formal approval by the Queen.
Coyle, who is already a BBC Trustee, spent eight years at The Independent up to 2001, before setting up her own consultancy specialising in the economics of emerging technologies.
She served on the Competition Commission from 2001 to 2009, and recently published a book about sustainable economics, titled The Economics of Enough.
The recruitment process for a new vice-chair began last June, but was delayed while a successor was found to the outgoing BBC Trust chairman, Sir Michael Lyons.
Lyons, who will step down as BBC chairman next month, making way for Lord Patten, welcomed Coyle's appointment.
He said: "Diane has made an important contribution to the work of the Trust in its first four years, particularly in leading its work on public value.
"I'm sure that in this expanded role Diane will be looking forward to the opportunity to bring her wisdom, insight and consistent good humour to even more of the Trust's work."