Nomura Holdings has been forced to cut costs to weather tough business conditions as it tries to move past an embarrassing insider trading scandal that led to the resignation of its chief executive last year.

Nomura has embarked on an aggressive $1.0 billion cost-cutting plan through to March 2014, a strategy credited for its 20.1 billion yen ($221 million) net profit in the October-December quarter.

Revenue in the period slipped four percent to 389.1 billion yen, but Nomura said the drop was unrelated to its core businesses.

"We had a solid third quarter with all three business divisions and all regions profitable on a pre-tax basis," Nomura chief executive Koji Nagai said in a statement.

"Our retail business reported its highest quarterly sales for the current fiscal year, with robust demand for equities and investment trusts."

In October Tokyo's stock exchange imposed a record fine of about $2.5 million on Nomura in the wake of the insider trading scandal which prompted the resignation of its chief Kenichi Watanabe.

A company report said the firm's sales staff tipped off clients about share sales and information often flowed freely between the sales department and Nomura's investment banking and research side, which is usually barred.

Authorities are carrying out a wide-ranging probe into insider trading which, although illegal in Japan, is widespread and carries only token penalties.