Associate partners Julius Duncan and Melanie Gerlis are set to leave the firm in the next few weeks.
Duncan, a former presenter and reporter for the FT Group, has quit Finsbury after five years and is set to join Southampton-based marcoms group Lawton.
Gerlis, who has been an important figure in Finsbury's financial services practice for the past nine years, is planning to study an MA in Art funded by auctioneer Sotheby's.
Duncan worked for Finsbury clients Royal & Sun Alliance and GCap Media, handling PR around the former's £1bn rights issue in 2003 and the latter's creation through the merger of radio groups Capital Radio and GWR earlier this year (PRWeek, 13 May). He also worked on Finsbury's account with Cable & Wireless.
Gerlis works for Finsbury clients Standard Chartered and the London Stock Exchange.
Gerlis, Duncan and Finsbury founder Roland Rudd all declined to comment.
Duncan will replace Debbie Greenwood at Lawton, who quit as director of the group's ten-strong PR division, Lawton Public Relations, earlier this year.