Nasdaq 100 Leaders and Laggards: FMCN YHOO

The index, which includes 100 of the largest nonfinancial securities listed on the Nasdaq Stock Market, lost 64.72 points, or 3.2 percent, to 1,990.39. Only two stocks rose on the index during the session.

The broader Nasdaq composite fell 75.38 points, or 3 percent, to 2,474.56.

Focus Media Holding Ltd. shares dropped $5.70, or 15.5 percent, to $31.09. The Chinese advertising network operator slashed its annual outlook due to the effects of a May earthquake.

Shares of United Airlines operator UAL Corp. shed $1.47, or 14.5 percent, to $8.64. The company said Friday it has reached a deal with an employee union that will give 600 flight attendants the option to voluntarily leave their jobs.

Shares of Irish budget airline Ryanair Holdings PLC slipped $3.01, or 9.5 percent, to $28.82.

On the gaining side, shares of Yahoo Inc. rose 8 cents to $26.44. Activist investor Carl Icahn urged Yahoo Friday to say it's willing to sell for $49.5 billion--about $2 billion above Microsoft Corp.'s last offer for the Internet portal.

Shares of Cephalon Inc. added 79 cents to $69.12. A Lehman Brothers analyst kept an "Overweight" rating on Cephalon Friday, citing updated reimbursement guidelines adopted by the Centers for Medicare and Medicaid Services for oncology drugs.