Financier J. Christopher Flowers is in talks to buy a stake in Brazil’s Banco BTG Pactual SA as part of an investor group that includes Government of Singapore Investment Corp., three people with knowledge of the deal said.

Andre Esteves, the Brazilian billionaire who controls Rio de Janeiro-based BTG, is in talks to sell about 15% of the firm to the group for about US$1.5 billion ($2 billion) to fund expansion, according to the people, who asked not to be named because the plans are private. An announcement may come as early as this week, the people said.