She joins Huntsworth next month and has been tasked with better integrating the group's PR shops, which include Harrison Cowley.
Clarke said a priority was to retain the firm's separate identities while looking at opportunities for multi-agency involvement when pitching for clients.
'At the moment there are various brands that are well known and respected in their own right and there are no plans to alter that, but when it comes to the bigger pitches I will look at where brands' areas of specialism can get involved,' she said.
Clarke added that she will initially be looking at the PR agencies in the group but in the long-term will be looking at joint pitches with the group's other marcoms businesses.
Clarke is also tasked with looking at closer integration between agencies with existing clients and has a direct reporting line to Huntsworh group CEO Lord Chadlington, who described the hire as 'a great coup for us'.
Her appointment comes three months after an acquisition spree by Huntsworth, when it bought Windsor-based consumer specialist Elizabeth Hindmarch PR, Thomson Financial's investor relations arm Global Consulting Group and boosted its Harrison Cowley operation in Scotland with the acquisition of the regionally based corporate firm Atlantic PR.
This is Clarke's first appointment since departing WS a year ago, when she was made redundant as part of a cost-cutting drive following the merger of Weber Shandwick Worldwide and True North's BSMG Worldwide.