All-night negotiations involving dozens of investment bankers concluded as WPP triumphed with a £266 million offer for indebted Cordiant.
Cordiant assets are likely to be aligned with Red Cell in Europe, Young & Rubicam in Asia and J. Walter Thompson in the US. Sorrell said: "We're working with Cordiant people and clients to determine the best fit and this will result in parts of Cordiant working closely with parts of WPP."
WPP's triumph is likely to lead to the removal of the Bates name in many markets. However, WPP and Cordiant have some shared clients including Pfizer with JWT and BAT with Ogilvy. Sorrell said: "We will retain the Bates name where it makes sense."
Because of conflict with its global Ford business, WPP is expected to have to fight to retain Bates' Seat account. Sorrell refused to comment, but it's understood that WPP's favoured solution is to create a Bates-branded Barcelona-based operation to house Seat.
WPP is committed to keeping Cordiant's below-the-line network 141 as a standalone business.
Sorrell expressed faith in Toby Hoare, the chief executive of Bates Europe.
He will work on integrating Bates clients with WPP until the end of the year. Looking to the future, Sorrell said: "I hope we find something interesting for him."
The level of redundancies is unclear. Cordiant employs more than 9,000 people but this will be reduced following the sales of Scholz & Friends, Financial Dynamics and George Patterson Bates in Australia. However, the merger of back office functions will lead to heavy redundancies.
Hoare said: "There will be a good future for a lot of our people and clients within WPP. Bates people deserve to be working for a successful company and WPP will offer them some of their pride back."
The WPP offer is set to be approved by Cordiant shareholders later this week. It follows an intense bidding process that ended on Monday when WPP trumped an offer from Publicis and the US hedge fund Cerberus.
Maurice Levy, the chief executive of Publicis, said: "I did not wish to lead Publicis Groupe into a bidding battle since we consider our last offer both fair and reasonable."
Levy also said Publicis had been assured that it would be able to buy out Cordiant's 25 per cent stake in ZenithOptimedia Group.
WPP has offered Cordiant creditors £256 million towards its £262 million debt and a nominal £10 million to Cordiant shareholders. Investors in Cordiant have expressed their anger at proposed severance payments due to the Cordiant chief executive, David Hearn, and the finance director, Andy Boland.