U.S.-based Advent International, a private equity firm, plans to invest 1.9 billion reais ($485.66 million) in retailing major Walmart's existing stores in Brazil as part of an agreement with Walmart.

In June, Walmart announced it sold an 80 percent stake in its Brazilian operations to Advent, partially exiting an underperforming business and taking a non-cash charge of roughly $4.5 billion.

Advent is deploying the money in three installments. The first two capital raises will total $183.9 million each.

The first was already completed and the second is expected for next year. The remaining amount will be invested by 2021.