Wilmington Trust Co on Friday sued three former bankers who defected to Citigroup Inc's private bank, claiming they took trade secrets and are using the information to attract clients.

The suit in Delaware Chancery Court names Barbara L. McCollum, Robert D. Rosenberg and Paul T. Gordon, who are among a team of five that left for Citi after Wilmington Trust agreed in November to be bought by M&T Bank Corp for $351 million.

The lawsuit alleges that the bankers worked to remove and disclose confidential and proprietary information belonging to WTC in breach of their confidentiality agreements, and are now using such information to wrongfully solicit WTC's clients.

The suit seeks temporary and permanent injunctions preventing the bankers from working for Citi until no further damage can be done and prohibiting them from soliciting or accepting work from Wilmington Trust's clients for a period sufficient to protect WTC's goodwill.

Citi spokesman Mark Costiglio declined to comment on the suit. McCollum could not be reached. Rosenberg and Gordon did not immediately return calls to their homes in Pennsylvania.

Citi hired the bankers in its Philadelphia office to work with very wealthy clients, endowments, foundations and owners of privately held businesses in Pennsylvania and Delaware. At Wilmington Trust, they also worked on a team catering to wealthy clients in the region.

McCollum, who was with Wilmington Trust for more than 30 years, was a vice president and the team leader. Rosenberg and Gordon also were vice presidents and all three received substantial compensation, according to the suit.

The lawsuit also says that Wilmington Trust's Wealth Advisory Services group, where the three bankers worked, was a major catalyst driving M&T's decision to partner with

The merger is expected to be completed in April, according to the lawsuit.

After accepting jobs with Citi, the three bankers conspired and plotted to recruit current employees in the WAS group to leave WTC and commence work with Citi, the suit says.

(Additional reporting by Dan Levine in San Francisco; Editing by Gary Hill)