Brothers Behind $46 Billion Bank Begin Restructuring Empire (1)

One of Brazil’s wealthiest families has kicked off a major ownership restructuring of their stake in Itau Unibanco Holding SA, Latin America’s most valuable lender.

Brothers Fernando and Pedro Moreira Sallesare buying out their siblings, Joao and Walther, at the investment firm that controls the family’s Itau stake, according to a regulatory filing. Joao and Walther own about 10% of the bank, a holding currently valued at $4.6 billion.

The purchases will be executed with several payments spread across years, according to a person with knowledge of the matter, who asked not to be identified because ...