Japan's Mizuho Financial Group Inc <8411.T>, Sumitomo Mitsui Financial Group <8316.T> and Mitsubishi UFJ Financial Group Inc <8306.T> are likely to have each achieved net profits of over 100 billion yen ($1.14 billion) for the April-June period, the Nikkei business daily said on Sunday.

The country's major banks have struggled since the middle of 2007 as losses from cleaning up bad loans ate into profits.

But the report said banks had enjoyed increased profits in the first three months of this financial year from trading operations and suffered smaller losses on bad loans amid fewer major bankruptcies.

Mizuho, which had a loss of 4.4 billion yen a year earlier after being hit by losses on credit default swaps, appears to have secured a profit of about 150 billion yen for the three months ended June, the Nikkei said. It was helped by increased profits from its trading business.

SMFG is likely to have achieved a profit of between 150 billion and 200 billion yen, up from the previous year's 72.7 billion yen, the report said, without citing sources.

MUFG is expected to report a profit of more than 100 billion yen, against a 75.9 billion yen profit a year ago, the report said.

The banks are under strong pressure to improve their core lending operations, however, as long-term prime rates are at their lowest levels in five years, the report also said.

(Reporting by Mariko Katsumura; Editing by Ron Popeski)