Allwood, who will report directly to the new chief executive MacLennan, spent four years at Orange, where he was responsible for aligning Orange UK with its parent company France Telecom.
Previously, he spent 11 years at News International in senior financial positions, plus a stint at BSkyB where he worked closely with Rupert Murdoch.
He has also worked at the Mirror Group Newspapers as a finance director and later deputy chief executive, where he worked alongside MacLennan.
MacLennan said: "John has one of the best newspaper business brains around. He has extensive experience across the media and we are delighted to have him on board."
Sir David and Sir Frederick Barclay took the reins at the Telegraph Group following Lord Conrad Black's failure to block the sale in July this year. The brothers reportedly paid £729m for the newspaper group.
The appointment comes just two months after the the brothers lured Associated Newspapers group managing director Murdoch MacLennan to be chief executive at Telegraph Group.
MacLennan had been the group managing director of Associated for 10 years. He is a newspaper executive with a large amount of industry experience.
The decision to appoint Allwood so soon after MacLennan, has sparked rumours that the Barclay brothers may be planning to radically overhaul the company.
The Telegraph Group declined to comment on Allwood's appointment at the time of writing but said they will be issuing a statement shortly.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .
.jpg)
.jpg)