The agency becomes known as Burnside Public Relations and comes hard on the heels of Incepta's agreement to merge with Huntsworth. Citigate originally acquired Burnside PR back in 1995, marking its entry into the province.
The eponymous consultancy has been dormant since then, with Burnside himself having been managing director of Citigate Northern Ireland. But Incepta opted to sell the firm back to him late last month.
The consultancy has 15 clients, including the International Fund for Ireland and charities RNLI and Rethink.
According to Burnside, it has scored a number of successes in securing planning permissions and altering licensing laws.
Earlier this year it secured a government agreement on behalf of the Police Federation of Northern Ireland to fund the 'cold case' review, which involves the reinvestigation of more than 2,000 unsolved murders in the province.
Incepta continues to have a presence in Northern Ireland through its Citigate Smarts consumer public relations shop.