* To list ADSs on NYSE under symbol "BSAR"
* To use proceeds to fund expansion (Adds details on Argentine share offer, IFR report)
BUENOS AIRES May 26 Banco Santander's (SAN.MC) (STD.BA) (RIO.BA) Argentine unit, Banco Santander Rio S.A., filed with U.S. regulators on Thursday to raise up to $100 million in an initial public offering of American depositary shares.
The largest private sector bank in Argentina said it would use the proceeds to expand its network of branches and ATMs, bulk up its loan portfolio and for acquisitions.
The bank told the U.S. Securities and Exchange Commission in a preliminary prospectus that Band of America Merrill Lynch, JPMorgan and Spain's Santander were underwriting the IPO.
The company intends to list its ADSs on the New York Stock Exchange under the symbol "BSAR."
For the year ended 2010, the company earned $558.0 million in net interest income.
In the filing, the company said its listing on the NYSE would consist of primary and secondary shares. It did not reveal how many American depositary shares it plans to sell or the expected price.
Each ADS represents four Class B shares of Banco Santander Rio S.A.
In conjunction with the IPO, the bank also intends to offer Class B shares in Argentina, subject to the local market regulator's approval.
Bank officials were not immediately available to provide further information.
In mid-March, shareholders of Banco Santander Rio authorized an increase of up to 145 million Class B shares, which traders said would be worth about $450 million.
The amount of money a company says it plans to raise in its first IPO filings is used to calculate registration fees. The final size of the IPO can be different.
Thomson Reuters news service IFR reported last week that Santander's listing of its Argentine subsidiary could bring in as much as $1 billion. (Reporting by Jochelle Mendonca and Vidya L Nathan in BANGALORE; Additional reporting by Walter Bianchi in Buenos Aires; Editing by Sriraj Kalluvila and John Wallace)