It’s been 15 months since ALM first revealed the merger negotiations between O’Melveny & Myers and Allen & Overy, and even longer since the discussions began behind the scenes.

The talks have stretched on much longer than expected, said several people informed on their progress, who cited hurdles such as choosing a name for a combined firm and the task of building consensus. The delays, in turn, carry their own risk, with industry experts warning that the passage of time in merger discussions can fuel uncertainty among firm lawyers, important lateral recruits and clients.