Hunter, who left Railtrack last August, replaces Ghassan Karian, who departed to join ICI as internal comms director two months ago (PRWeek, 17 May).
At defence, aerospace, marine and energy giant Rolls-Royce, Hunter will lead internal comms at a corporate level.
He confirmed he will be carrying out a review of internal comms strategies and programmes, including the project work recently handed to Fishburn Hedges.
FH was hired in April to analyse internal comms across Rolls-Royce's global business units, but the work was put on hold following Karian's exit.
Hunter said: 'A key element of the role is going to be working with the leadership team and internal comms colleagues worldwide to help people make informed decisions by focusing relevant communications up, down and across the business.'