JPMorgan Chase's ( JPM) second-quarter profits more than tripled from a year ago, but revenue at the nation's third-largest bank fell short of Wall Street expectations. A year ago, the New York-based bank's results were hobbled by a massive $1.2 billion litigation charge to settle claims arising from the WorldCom and Enron litigation. But the bank's overall results in the most recent quarter were still impressive. JPMorgan posted strong gains in revenue from investment banking, trading and asset-management fees. In the quarter, JPMorgan earned $3.54 billion, or 99 cents a share, compared to $994 million, or 28 cents a share, a year ago. Total net revenue at the bank rose 19% to $14.94 billion. The bank handily surpassed the 87 cents a share consensus estimate of Wall Street analysts. But revenue fell short of the Thomson Financial consensus estimate of $15.33 billion. Net revenue at JPMorgan, while up 19% over the prior-year period, declined by 1% from the first quarter of this year. The big gain in year-over-year revenue was fueled by a surge in revenue from principal transactions, which includes proprietary trading. In the quarter, principal transaction revenue rose 263% to $2.63 billion. But compared to the first quarter of this year, principal transaction revenue rose a scant 1%. Over the years, JPMorgan has had an uneven track record in generating revenue from trading bonds, stocks and commodities, especially when compared to other commercial banks and Wall Street investment firms. JPMorgan CEO Jamie Dimon has said one of his priorities is improving the performance of the bank's traders. Fees from investment banking work rose 43% from a year ago to $1.37 billion. Asset management fees and commissions on customer stock trading rose 21% to $2.93 billion.