Smith Barney has obtained a restraining order against a broker and filed a federal lawsuit and arbitration claim, accusing him of using confidential information to solicit business for a new employer.

Brian Dillon, who left Smith Barney, the brokerage arm of Citigroup (C) in New York, on May 15, allegedly solicited its customers to transfer their accounts to Ameriprise Advisor Services, Inc., a unit of Minneapolis-based Ameriprise Financial Services Inc. (AMP), according to a complaint filed on May 19 in U.S. District Court in New Jersey.

A restraining order obtained against Dillon and Ameriprise, filed on May 20, required the return of Smith Barney's confidential information, such as documents and computer data, within 24 hours. The federal court order also bars Dillon and Ameriprise from soliciting certain accounts, pending the outcome of an arbitration before a Financial Industry Regulatory Authority, or Finra, panel, according to the order.

Dillon worked for Smith Barney in Stamford, Conn., and is currently employed as a registered representative by Ameriprise in Paramus, N.J., according to the complaint.

The complaint says that Smith Barney will suffer irreparable harm as a result of the alleged actions by Dillon and Ameriprise.

A Smith Barney spokesman declined to comment Tuesday.

An Ameriprise spokesman declined to immediately comment.

An attorney for Dillon in the Radnor, Pa., office of Fisher & Phillips LLP didn't immediately return a call requesting comment.

-By Suzanne Barlyn, Dow Jones Newswires; 201-938-4546; suzanne.barlyn@dowjones.com

-By Jessica Papini, Dow Jones Newswires; 201-938-2437; jessica.papino@dowjones.com