Overseas expansion is a priority for the architectural practice formed out of the merger of Abbey Hanson Rowe and Holford Associates.

The pair announced the merger deal, which will create a new top 10 practice, this week after nine months of talks.

The practice, which will have 330 staff, will start trading from 5 April under a name that is yet to be decided. Abbey Hanson Rowe chairman James Handley said the main aim of the deal was to give the firms the critical mass they need to expand.

He said: "At the moment, we are concentrating on getting the new firm up and running. Our main priorities will be to further strengthen our London office and move overseas in the medium term – that is where we believe the markets are." Abbey Hanson Rowe is the larger partner, but Handley insisted the deal is a merger, not a takeover. Both firms will bring their combined capital to form the equity in the practice.

Holford already has an office in Dubai. Handley said the new firm will be looking at expanding into markets including Kazakhstan, Poland, Bahrain, Saudi Arabia and possibly South Africa.

Handley said: "We drew up a business plan a couple of years ago with the intention of doubling our size over the next five years. We bumped into Holford's, which had the same idea, so we started talking. We discovered they were like-minded people and we got on well, and so the deal went from there." The firm will continue to operate as a partnership but would look at moving to company status in the long run.

Handley said no redundancies are expected.