Bank of America ( BAC) isn't wasting any time in bouncing back from this month's earnings disappointment.Just a week after the big Charlotte, N.C., financial institution posted a sharp drop in third-quarter earnings, BofA is cutting 3,000 jobs, mostly at its Global Corporate and Investment Banking unit. The firm is also changing the head of that unit and launching a strategic review of its investment banking business. CEO Ken Lewis told analysts last week after announcing a 93% profit drop at the unit that "I've had all the fun I can stand in investment banking at the moment." Lewis also told investors on the bank's earnings call that layoffs were pretty much a given at BofA, which has grown rapidly through acquisitions in recent years. "We're going to look at every single business," Lewis said in response to analyst questions. He added that the bank would "see where our strengths are and where they're not and act accordingly." BofA employs 220,000 workers, though investment banking is just a fraction of that. The layoff announcement comes on the heels of bad news across the banking sector, where Citi ( C), UBS ( UBS) and Merrill Lynch ( MER) have been pounded by massive writedowns on bad debt. One casualty of Wednesday's shakeup is BofA investment banking chief Gene Taylor, who is retiring at the end of the year. Brian Moynihan, who has headed Global Wealth and Investment Management at Bank of America since 2004, will replace him.