Japan's Mizuho Bank was charged negative rate on deposits at BOJ

TOKYO (Reuters) - Japan's Mizuho Bank was charged negative interest rates on some of its deposits at the central bank in mid-July through August, a spokesperson said, as the main banking unit of Mizuho Financial Group piled up reserves.

The amount of megabanks' reserves on which negative rates were charged during the period stood at about 903 billion yen ($6.75 billion), BOJ data showed on Tuesday.

It is the first time in seven months that negative rates were charged on reserves held by any of Japan's megabanks, which also include those owned by Sumitomo Mitsui Financial Group and Mitsubishi UFJ Financial Group.

The Bank of Japan did not give a breakdown of which banks held the reserves, but the spokesperson for Mizuho Bank said the bank held 902.8 billion yen in BOJ reserves with negative rates.

Under its current policy, dubbed yield curve control, the Bank of Japan imposes a 0.1% interest rate on a portion of excess reserves financial institutions park with the central bank.

Japan's megabanks have mostly avoided paying the interest by shifting money out of BOJ reserves. But Mizuho increased deposits this time as it shifted funds away from short-term Japanese government bonds due to their plunging yields, the spokesperson said.

($1 = 133.7700 yen)

(Reporting by Makiko Yamazaki; Editing by Jan Harvey)