Stocks in the news: UBS, Staples, National Semiconductor

UBS (UBS) revised its 2008 loss wider by around $1 billion, and said earnings will be at risk for some time to come. Switzerland's biggest bank, posted a 20.9 billion Swiss franc ($18 billion) loss for 2008, 1.19 billion francs wider than figures reported on Feb. 10, and said it remains "extremely cautious" about the outlook for this year. UBS shares were 2.6 percent higher in premarket trade.

Staples (SPLS) reported its fiscal fourth-quarter profit dropped 14 percent to $286 million, or 40 cents per share. Analysts surveyed by Thomson Reuters predicted earnings of 42 cents per share on sales of $6.82 billion. SPLS shares are declining 4.7 percent in premarket trade.