Spanish bank Santander (NYSE: STD) has announced that it plans to offer a 15% stake in its publicly traded Brazilian unit - its largest operation in Latin America - and will be incorporating its insurance, brokerage and other subsidiaries.

Santander, which controls 97.9% of Santander Brasil's shares trading on São Paulo stock exchange Bovespa, will offer up to a 15% stake in new shares, CEO Alfredo Sáenz said during the bank's second quarter earnings presentation.

The CEO also upped the bank's estimate of Santander Brasil's synergies for 2009 -the "first year" in the merger of the unit with Banco Real, the former ABN Amro subsidiary that it got in an October 2007 deal - to 1.30bn reais (US$688mn) from a previous estimate of 800mn reais.

In filings with Bovespa on Wednesday, Santander Brasil said it would ask its shareholders to fully incorporate its insurance subsidiary Santander Seguros, asset manager and brokerage Santander Brasil Asset Management DTVM and former ABN Amro acquisition Banco Comercial e de Investimento Sudameris (BCIS).  ABN Amro bought a 94.6% stake in Sudameris from Italian bank Intesa in 2003, but only began to bring the assets under its branding in 2007.

The vote on the plan, which also includes the cancelling of 13.6mn ordinary shares and 11.8mn preferred shares in Santander Brasil held in treasury, is set for August 14, the filings said. In a subsequent stage, the bank said it will incorporate other subsidiaries into the group.

In Latin America, Santander holds a 99.3% stake in Santander Río in Argentina, 76.7% of Santander Chile, 97.9% of Santander Colombia, and 75.0% of its Mexican subsidiary, among other holdings in other operations.