Stocks Open Lower on Mixed Earnings News

On the upside

AO Smith (NYSE: AOS) posted lower profits that beat estimates.  The company makes water heating equipment and electric motors.

Investors were surprised by Citigroup's (NYSE: C) latest quarterly profit, much of it due to gains from the sale of its Smith Barney unit.

On the downside

Marshall & Isley (NYSE: MI) posted a smaller loss than expected as the financial services company wrote down problem credit issues.

Bank of America (NYSE: BAC) reported a sizable quarterly profit, but warned of continued weakness in its credit portfolio.

General Electric (NYSE: GE) posted lower profits due to eroding performance at its finance and industrial goods units. 

Google (Nasdaq: GOOG) posted higher revenues and profits, but investors focused on the search engine's slowing rate of growth.

In the broad market, declining issues outpaced advancers by a margin of nearly 5 to 3 on the NYSE and by 5 to 4 on Nasdaq. The Russell 2000 which tracks small cap stocks slipped 3 points to 518.