WPP - the advertising and communications giant run by Sir Martin Sorrell - and Finsbury are set to reach a decision on the proposed takeover of the financial PR firm by the end of the year.
Talks have been ongoing since the beginning of the year. Finsbury is currently understood to be holding out for the right amount before signing a deal with Sorrell.
Finsbury and the WPP boss declined to comment, but industry sources say both parties have agreed an initial payment of pounds 15 million to pounds 20 million, but are yet to settle on the earn-out, which could value the company at between pounds 35 million and pounds 50 million.
WPP, which already owns financial PR outfit Buchanan Communications, has also approached fellow City PR consultancies Brunswick and The Maitland Consultancy.
Finsbury has been courted by at least four groups since it was formed six years ago by ex-Financial Times journalist Roland Rudd and former Brunswick executive Rupert Younger.
Ludgate approached Finsbury two years ago followed by the Interpublic and Omnicom groups, which aimed to merge the firm with their financial PR divisions, Shandwick and Gavin Anderson and Company respectively.