He was a former deputy chairman of Burson-Marsteller, then Edelman, and a founding partner of ReputationInc.
Diageo corporate relations director Ian Wright paid tribute to Whittaker, describing him as 'a really wonderful friend and mentor to many'.
A note from ReputationInc bosses Tom Wyatt and John Mahony read: 'Nigel was a great man, with fabulous wit, and was a tremendous professional to work with. He should have enjoyed a well deserved retirement ...
after giving his all to the legal and business world. Unfortunately that was not to be.'