[ by Melanie Gretchen ] Bank of America enjoyed a wave of success with its announcement of Q1 results.  Both quarterly earnings and revenues exceeded analyst expectations, propelling BAC shares higher in premarket trading.  Share price pulled back into negative territory during the day, however, following the trading session's overall downward trend. First Quarter Results. BofA reported net profits of $653 million, or 3¢ a share, on revenues of $22.5 billion.  The lower earnings included one-time expenses.  Revenues were down 17% from last year's $27 billion.  The top and bottom lines were affected by accounting charges for how the bank's debt is value. Excluding those charges, the company's revenue was down 2.5% to $27.3 billion, while its profits were up 34.8% to $310 million.  The bank's operating income was 31¢ a share  and was ahead of analyst estimates of 12¢ a share.  Its revenues met expectations. Investment Banking Unit. The company’s global markets unit swung to a profit of $798 million, compared with a loss of $768 million in the Q4 of 2011.  Revenue at the division, which includes Bank of America Merrill Lynch, more than doubled from the prior quarter, but was down from the first quarter one year ago.   [CNBC, 4/19/12].