The sum is the largest in any half year since 2013 and exceeds the total amount of capital raised over the previous three years combined, according to Baker Mackenzie.
The local operations of Spanish giants Santander and BBVA post positive results.
With President Temer fighting for his political survival, key pension reforms could be delayed.
The Mexican consumer lender saw double-digit annual loan growth, partially offset by higher funding costs.
The Selic rate has reached its lowest level since 2013.
The banks - Banco Security, BICE and Banco Internacional - have accused BancoEstado of charging "discriminatory rates."