Japan's third-largest lender by assets reported April-June profit of 162.4 billion yen ($1.50 billion) compared to 161 billion yen in the same period a year earlier. The profit was also buoyed by a 28.2 billion yen gain from selling stocks of corporate clients.

For the full year through March, Mizuho kept its profit forecast at 470 billion yen, which was almost five times higher than the profit of the previous year. That compared with the 472.1 billion yen average of 11 analyst estimates compiled by Refinitiv.

The bank's domestic lending business remained tepid, with a loan-to-deposit rate margin - or difference between interest earned on loans and paid on deposits - falling to 0.78% from 0.83% a year earlier.

Japan's banks have struggled in the traditional lending business in a low interest rate environment. That is set to continue as the central bank on Tuesday said it would retain its aggressive monetary policy.

Mizuho's markets division, which includes its trading business, pushed up its bottom line by 15.6 billion yen from a year earlier. Its outstanding foreign loans increased to $244.3 billion, up 9.5% from a year ago.

It booked a 680 billion yen ($6.26 billion) write-down in the last financial year, with 500 billion yen from fixed assets and 180 billion yen incurred restructuring its securities portfolio of foreign bonds. ($1 = 108.5600 yen)