A law firm faces conflict allegations over its projected $3.5 million fee for representing shareholders who obtained no monetary or equitable relief in a class action settlement over the merger of drug giants Merck and Schering-Plough.

Class member Allan Marain, a lawyer in New Brunswick, N.J., filed papers Wednesday opposing the settlement, which a federal judge has tentatively approved, and seeking sanctions against the firm, Carella, Byrne, Cecchi, Olstein, Brody & Agnello in Roseland, N.J.