Nomura Holdings Inc. said Thursday its group pretax profit for the fiscal first half soared 291.9 percent from a year earlier to 159.25 billion yen, due chiefly to the robust stock market.

The brokerage giant said that trading income surged 123 percent to 147.53 billion yen in the half-year period, while commission income rose 11.1 percent to 89.72 billion yen. Overall revenues grew 33.3 percent to 573.38 billion yen.

In a consolidated earnings report calculated under U.S. accounting standards, Nomura said it posted a net profit of 86.69 billion yen, down 33.9 percent, due mainly to accounting technicalities.

Nomura provided no earnings forecast for the full year through March 31 as stock market fluctuations make doing so difficult, it said.