SAO PAULO (Reuters) – Brazil’s largest private-sector lender, Itaú Unibanco Holding SA, will launch an instant payments platform by the third quarter that uses QR codes, adding fuel to the fierce competition among card processors.

Itaú’s new platform, called Iti, will work through an app connecting individuals and merchants and will be available to both clients and nonclients of the bank, it said on Monday.

Merchants using Iti will pay a fee of 1% per transaction and will receive payments instantly – cheaper than fees currently charged by many card processors. The app also does not require merchants to buy or rent card reader machines.

Shares of Brazilian card processors, such as PagSeguro Digital Ltd, StoneCo Ltd and Cielo SA, fell sharply after Itaú’s announcement.