Lehman Brothers said quarterly profit more than doubled thanks to higher revenue from bond trading and underwriting, stock sales and mergers.
Lehmans, one of Wall Street's largest investment banks, said net income rose to $670 million from $301 million, a year earlier.
Lehman said net revenue totalled $3.1 billion, up 84 per cent from a year earlier and up 37 per cent from the prior quarter.
The company said it benefited from "robust customer flow activity" throughout much of its capital markets business. It also said higher confidence in the US economy and corporate profitability led to increased merger activity and equity offerings.
Lehman is the first of four large US investment banks expected to report quarterly results this month. Bear Stearns is expected to report tomorrow, Morgan Stanley on Thursday and Goldman Sachs next week.