Merriman Curhan says under SEC investigation

NEW YORK, May 29 (Reuters) - Merriman Curhan Ford (MERR.O), an investment banking and equity research firm, said on Thursday regulators were investigating the firm's trading in certain stocks, and its supervisory system.

Merriman said it was cooperating in the investigation by the U.S. Securities and Exchange Commission. The U.S. attorney's office in San Francisco was also investigating.

After an internal inquiry, the firm said it suspended a retail broker for violating its policy regarding use of client account information.

The broker appeared to have assisted a retail client in obtaining loans from third parties using information from the accounts of other retail clients, Merriman said in a regulatory filing.

The firm was neither a borrower or lender in any of the loans, it said.

All of the broker's clients whose accounts were potentially impacted have been contacted, Merriman said. It continues to review the matter. (Reporting by Lilla Zuill, editing by Leslie Gevirtz)