MacLennan axed three senior executives including commercial director Mark Payne, group sales director Chris White-Smith and marketing director Dixon last month.
The 30-year-old Vanneck is the third major signing since MacLennan took over at the paper three months ago. Emap head of advertising Dave King and Orange UK boss John Allwood have been appointed executive directors.
Vanneck joined News International as a graduate trainee and has quickly risen up the ranks. In 2001, she was appointed as publisher of The Times online edition and successfully merged The Times and Sunday Times websites under one brand. She was also involved in the launch of the tabloid Times in 2003.
Prior to the three axed directors going, the Telegraph Group's managing director Hugo Drayton also went, departing soon after the Barclay brothers' £665m takeover and subsequent management shake-up instigated by former Associated Newspapers group managing director MacLennan.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .