Chilean bank Corpbanca and a Washington-based minority shareholder trying to block its merger with Brazil's largest bank, Itau Unibanco, have bolstered their PR operations amid a legal showdown.

chileCartica Management, a $2B DC-based asset manager and minority owner in Corpbanca that has sued Corpbanca and Itau in federal court to block the merger, engaged Kekst and Company for PR counsel. The company said June 13 that it wants to halt the "fraudulent transaction" – it accuses Itau of trying to skirt US regulators -- so that a new deal can be ironed out to "treat all shareholders equally."

Santiago-based Corpbanca, which is traded on the New York Stock Exchange, has FTI Consulting and Joele Frank, Wilkinson Brimmer Katcher in New York working the PR front, as well as the Chilean PR firm Simplicity.

Corpbanca said the lawsuit's claims are "entirely without merit" and that it will file a motion to dismiss the Cartica suit. The Chilean bank said Cartica is looking for a payout and special treatment.

Itau moved to acquire a large stake in CorpBanca in January.