Shares of Citigroup Inc, Bear Stearns Cos. and Lehman Brothers Holdings fell before the opening bell on Tuesday after Merrill Lynch downgraded the investment banks, MarketWatch reported on its Web site.

Lehman dropped 3 percent to $56, Citigroup shares fell 1.7 percent to $46.99 and Bear Stearns lost 1.9 percent to $110.05 in electronic composite trading.