The Burkitt name is expected to disappear as part of the plans. Its former chairman, Hugh Burkitt, left the agency eight years ago.
Burkitt made a number of redundancies when the John Lewis account went to Lowe. The loss halved its UK billings. Its main clients now include Schwarzkopf and Epson.
DDB London has also suffered lately, losing both senior management and flagship accounts including The Guardian, Lurpak and PG Tips.
It is currently without a chief executive. Stephen Woodford will be joining the agency from WCRS, but that agency is holding him to his gardening leave for now.
Michael Bray, the chief executive of DDB Europe, said: "DDB London is aware of the conversations taking place between Burkitt DDB and DDB Worldwide, but at this moment in time we have no comment to make."
Julian Calderara, Burkitt DDB's chief executive, added: "Burkitt DDB is in talks with DDB Europe about how the network can best assist the Smithfield office in controlling its cost base."