The two agencies are fully owned by the Press Association, the UK's news agency, and will become collectively known as TNR Communications.
Currently TNR specialises in TV, radio and online PR whereas PA Photocall offers the opportunity to hire PA photographers for PR events to submit images to the news wire.
The newly combined organisation is also launching a social media video service, Videocall, to take advantage of the massive explosion in online video communication.
MD Claire Southeard said: ‘TNR and PA Photocall have worked together very closely for three years, developing their reputations as providers of PR services with editorial integrity.
'However, the opportunities presented by our merger take us into a different league, not only because it brings together the talents of two very experienced and creative teams into one multimedia consultancy, but also because we can now offer a fully comprehensive range of communications services from our unique position at the heart of the Press Association.'