Stocks closed lower on Tuesday, as concerns about the credit crunch weighed on investor's minds. Financial stocks were out of favor again, after J.P. Morgan Chase downgraded a number of brokerages.

Bloomberg reported a senior company executive at Citigroup (C | Quote | Chart | News | PowerRating) said the bank "lost more money than it made from financial instruments based on U.S. subprime mortgages" (read more).

Merck (MRK | Quote | Chart | News | PowerRating) reaffirmed its 2007 outlook and forecast earnings growth in 2008 (read more).

Nokia (NOK | Quote | Chart | News | PowerRating) said it currently estimates operating margin in the range of 16-17% targeted within the next one to two years (read more).

Dell (DELL | Quote | Chart | News | PowerRating) announced a $10 billion share buyback (read more).

Dow Chemical (DOW | Quote | Chart | News | PowerRating) announced it is cutting 1000 jobs, or 2.3% of its work force (read more).

AutoZone (AZO | Quote | Chart | News | PowerRating) shares are surging after the company reported profit increased 7% on higher sales and improved profit margins (read more). AZO gained more than 18%.

CMGI Inc. (CMGI | Quote | Chart | News | PowerRating) is also surging after reporting a 17% drop in net earnings and backing its full-year 2008 outlook (read more). CMGI rose nearly 30%.

Sanderson Farms (SAFM | Quote | Chart | News | PowerRating) reported Q4 profit more than doubled (read more). SAFM shares jumped by almost 7%.