The trio have hired Beattie's former Aberdeen MD Zoe Corsi to head the four-strong team. Ex-Beattie consultants Isobel Pritchard and Natasha Fulford have also been hired.
Beattie Media is understood to be looking to replace all three. Agency CEO Gordon Beattie said: 'The impact on our business will be minimal. We are in discussions with people who can increase our activity in the oil, energy, retail, property and construction sectors in Aberdeen.'
Big's Aberdeen operation is now on the hunt for clients.
The agency, which has a head office in Glasgow and an operation in Edinburgh, already has 25 staff in Scotland.