BSMG Worldwide's UK chief executive Nan Williams has quit following disputes with its American parent company over strategy.
Williams, who started at the then Charles Barker as a graduate trainee in 1985, is to leave the company at the end of the year.
Although the official line is that she is leaving to pursue other interests, Williams is understood to have resigned following differences of opinion between London staff and the US parent, True North Communications.
True North has recently been subject to takeover speculation, increasing uncertainty for senior London staff.
Her departure was described as amicable, but it is thought Williams had grown frustrated with what she felt was a lack of investment in the BSMG brand in the UK after a string of recent acquisitions.
BSMG has in the last two years bought consumer PR firms Walker Williams and Lyons Waddell, public affairs shop GJW and City agency Square Mile (PRWeek, 24 November). Williams played a key role in negotiating the acquisitions but feels they need supporting with further investment to shore up the BSMG brand.
Her move follows a raft of senior departures from the original Charles Barker three years ago - when the agency took fees of pounds 6m, compared to projections of triple that for 2000. Public affairs head Laura Sandys and agency veteran Steve Gebbett have left, as have second tier staff including Kevin Redfern, Phil Anderson and Pete Bowyer.
BSMG European chairman Tim Sutton said Williams' post is to be taken by an external hire, expected to be confirmed within two weeks.
Williams is considering a range of global or European agency roles but has not ruled out setting up her own agency when contractual constraints are lifted next autumn.