Three Dublin law firms, including one of the oldest in the State, are to merge in order to enhance their competitiveness.

The firms - Orpen Franks, Tweedy & Co and Reeves - are merging to achieve "critical mass" against the large commercial legal practices which are increasing their share of the market. The combined practice will operate as Orpen Franks Solicitors and will employ 19 solicitors and 22 support staff in one office.

It is understood there is no financial consideration involved in the merger. The firms say another reason for the move is that the demand for legal services from clients is increasing in line with the boom in the economy.

"Clients are looking for additional services and it is easier to meet this demand by pooling the resources of three practices," said Mr John O'Donovan, managing partner of Orpen Franks. He will become managing partner of the enlarged firm.

He added that much of the additional demand was being created by the increase in mergers, acquisitions and disposals. The growth in the property market was also creating extra business for solicitors' firms.

Orpen Franks and Tweedy & Co are strong in the area of corporate law, while Reeves, established in 1703, has an extensive private client practice.

Partners will be drawn from each of three firms as well as representatives of Montgomery & Chaytor, with whom Orpen Franks merged four years ago.