Thu Mar 6, 2014 4:37pm EST

(Reuters) – Executives at Chile’s CorpBanca SA COB.SN pledged to disclose more data related to the lender’s merger with Brazil’s Itaú Unibanco Holding SA (ITUB4.SA) after an activist U.S. investor claimed the deal hampered the rights of minority shareholders.

The lender will unveil details about the deal, which makes Itaú the top CorpBanca shareholder, prior to a ballot on the merger, Claudia Labbé, CorpBanca’s head of investor relations, said during a conference call on Wednesday.

The deal requires the approval of two-thirds of CorpBanca’s shareholders.

U.S. investor Cartica Management LLC said in a letter to the CorpBanca board this week that the deal undervalued the company’s shares, and gave special benefits to Chilean billionaire Alvaro Saieh and his investment holding company, Corp Group. Saieh is the controlling shareholder of CorpBanca.

Cartica, which owns 3.2 percent of CorpBanca, published the letter to the board on Tuesday, confirming an earlier Reuters report.

CorpBanca Chief Executive Officer Fernando Massú told investors during the Wednesday conference call that board members are appraising Cartica’s letter.

However, Chief Financial Officer Eugenio Gigogne said that, based on assessments by the bank’s legal team, the arguments questioning the merger are “incorrect from a legal point of view.”

Gignone added that a merger had been considered as CorpBanca entered into talks with potential partners because “CorpBanca was never up for sale.”

Under Chilean securities law, there is no need for a public tender offer for outstanding shares when two companies merge.

Cartica’s move, a rare instance of investor activism in the region, threatens to upset Latin America’s largest banking merger since 2008.

Itaú did not have to launch a tender offer in Chile for CorpBanca because the deal did not give the Brazilian company more than 50 percent of the lender, executives said at the time. Under the terms of the deal, Itaú would have a 33.58 percent stake in CorpBanca through a shareholder agreement with Corp Group.

The new company, named Itaú CorpBanca, is expected to have a market value of $8 billion, about 10,000 employees and 390 branches.

DIVIDENDS, STRATEGY

Itaú shares jumped 2.8 percent on Thursday to 31.58 reais. CorpBanca slipped 0.8 percent to 6.531 Chilean pesos.

The executives reiterated during the call that annual pre-tax cost savings from the integration of CorpBanca’s Chile and Colombian units with those of Itaú should reach about $100 million. This compares with one-off integration costs of about $85 million.

About half of the synergies will come from payroll, both Massú and Gigogne noted, adding that branch closings will be assessed individually.

The executives also see strong growth potential for CorpBanca’s Colombian operations. Organic growth in Colombia’s banking system “is attractive,” with the potential to reach 16 percent a year, they added.

The executives also said CorpBanca will propose a 57 percent dividend payout ratio on 2013 net income, compared with the average of 50 percent in recent years. For the next eight years, the minimum cash dividend target is $370 million a year.

Going forward, CorpBanca will create a rule to maintain capital ratios at the average of the three largest banks in Chile and Colombia, or 20 percent above the regulatory minimum, Gignone added.