MD Andrew Lorenz has been appointed chairman of the financial communications practice, with head of financial services Geoffrey Pelham Lane becoming financial communications chief operating officer.
Senior partner Tony Danaher is now chairman of marketing communications, while partner David Lloyd has become chairman of public affairs and issues management.
The UK restructure has been mirrored by changes in America under FD US chief executive Declan Kelly. The three core US divisions have been named public affairs, investor relations and corporate communications.
Watson said the new structure had been adopted to reflect FD's expansion over the past three years from a business with 280 PROs to a 450-strong firm with more than 700 clients.
Last month, FD followed last July's acquisition of PA shop LLM Communications with the acquisition of Washington DC-based Dittus
Communications (PRWeek, 6 January).
The move followed the purchase in September of US consultancy Westhill Partners and UK property PR firm Tamesis Business Communications last January.
Watson has said that neither FD nor Advent is in talks with would-be acquirers, but there has been speculation that Advent could sell the agency three years after acquiring it.