It will be led by Malcolm Robertson and Andrew Wilson with Sir Angus Grosshart as chairman.
RLM Finsbury's Roland Rudd and James Murgatroyd will be on the board as well as The&Partnership's global chief executive Johnny Hornby.
Charlotte Street Partners will have a strategic partnership with The&Partnership, which launched last month and is a WPP-backed group of agencies that includes Halpern PR, ad agency CHI and social media agency The Social Practice.
Robertson is a former comms director of BAA and Wilson a former head of group comms at RBS. Grosshart is chairman of Noble Grosshart, the Scottish merchant bank he founded in 1969.