SAO PAULO, Oct 5 (Reuters) - Shares in payments company Getnet Brasil will start trading on the B3 and Nasdaq stock exchanges on Oct. 18 and 22 respectively, its current controlling shareholder Banco Santander Brasil SA said on Tuesday in U.S. and Brazilian regulatory filings.

The lender previously announced it is spinning off and listing Getnet as part of a larger overhaul in the payments businesses of Spain's Banco Santander, which are grouped in PagoNxt, of which Getnet will be a unit.

"This strategic step will enable Getnet Brazil to unlock the full potential of its businesses as part of PagoNxt," said Getnet CEO Pedro Coutinho in a statement.

Santander said in a statement that it plans to expand Getnet to more countries in Latin America and Europe. Currently it operates in Brazil, Mexico, Argentina, Chile and Uruguay.

Brazil's third-biggest card processor, Getnet posted net income of $37.6 million in the first half of the year, with a net income margin of 14.9%.

Santander Brasil's stockholders will get 0.25 share of Getnet for each of their existing shares in the bank and 0.125 American Depositary Share of Getnet per ADS of the lender.

Getnet will make its debut in a vastly altered landscape for once high-flying Brazilian payments companies like Cielo SA , PagSeguro Digital Ltd and StoneCo Ltd , which have tumbled this year amid fierce competition. (Reporting by Carolina Mandl, in Sao Paulo, and additional reporting by Jesus Aguado, in Madrid; Editing by Cynthia Osterman)