The digital bank, backed by investors including Warren Buffett's Berkshire Hathaway and Softbank Group Corp, said it had 66.4 million customers in Brazil, its main market, up from 62.3 million at the end of June.

In Mexico, Nubank's user grew to 3.2 million users while adding 400,000 in Colombia, the fintech said.

The fintech, considered one of Latin America's chief proponents of expanding access to the financial system, also said its investment services business in Brazil surpassed 6 million active clients.

Its crypto exchange, launched in July, had 1.8 million clients, Nubank said.

(Reporting by Peter Frontini; Editing by Josie Kao)