Kicking-off a series of earnings reports from the nation biggest banks in the coming days, JP Morgan Chase said Friday that it earned $1.31 a share in the first quarter of 2012, compared with $1.28 a share in the same period a year ago. On a reported basis, revenue rose 6 percent, rising to $26.7 billion, from $25.2 billion.

Analysts had been expecting JPMorgan Chase, the country’s biggest bank, to earn $1.13 a share for the quarter on revenue of $24.7 billion. The company has benefited from improving capital markets activity as well a steady recovery in consumer credit and business lending.

Several brokerages have raised their ratings on JPMorgan shares in recent weeks, and the stock has soared this year from $33 in December to $44.84 on Thursday. Unlike rivals like Citigroup and Bank of America, JPMorgan Chase came through the financial crisis of 2008 mostly unscathed, despite mortgage-related losses.

Last month, the bank got the go-ahead from the Federal Reserve to hike its dividend and buy back billions more in stock. Nevertheless, the company and other big banks are contending with sluggish revenue growth as new federal regulations eat into fees for consumer banking and low interest rates keep credit spreads tight.

Despite the run-up in the stock market, trading volumes in the first quarter haven’t been especially robust. At J.P. Morgan’s investment bank, revenue was down 11 percent, to $7.3 billion. Its net income was down 29 percent, to $1.7 billion.

The bank also faces tough comparisons with a strong first quarter in 2011, when healthy trading revenues and reserve releases lifted results.