The two Surrey-based agencies will work under the theblueballroom name from today following an informal collaboration, with the merger formally taking effect from next year.
The founding of thebluedoor, in 2008, was instigated by theblueballroom MD Sheila Parry, who sat as chairman on boards of both agencies, though the two management structures were separate.
Clients to be shared by the two agencies will include DP DHL, Mars Drinks, Mitsubishi Heavy Industries and Roche.
Parry, formerly a PR manager at DHL, who founded Theblueballroom in 2001, said: ‘This move demonstrates our understanding of what businesses need now. We are now working with big businesses that understand the power of comms.
'In our new form, our consultancy, concept and content experts will be able to work with organisations to understand, define and deliver compelling messages that shape opinion no matter where the stakeholder sits.’
Harrison, managing director at Thebluedoor, said: 'By now joining forces with an internal specialist that also influences the digital landscape, we can ensure we provide the most effective comms strategies possible to meet the needs of our clients’ entire business.’