Telecomunicaciones y tecnología
Stocks slide on bank worries and retail sales
* Citigroup tumbles more than 23 percent.
* December U.S. retail sales fall 2.7 percent.
* Dow falls 248.34 points, or 2.94 percent, to 8,200.22; the S&P 500 slides 29.12 points, or 3.34 percent, to 842.67; the Nasdaq Composite sheds 56.82 points, or 3.67 percent, to 1,489.64.
(Editing by Leslie Adler)