Best Buy dropped following a report that the consumer electronics retailer's founder Richard Schulze may be considering alternatives to his buyout plan.
Apple lowered the price of its MacBooks by up to $200 as it revamps its top-end laptops, fueling worries that the company's iPad may be cannibalizing Mac sales. Apple sold 4.1 million Macs in the December quarter, down more than 20 percent from the same period a year earlier.
Separately, Omega Advisors CEO and Chairman Leon Cooperman liquidated his position in Apple and purchased Facebook, according to an SEC filing. Apple declined, while Facebook rallied following the news.
Blackberry tumbled after National Bank released a bearish note on the smartphone maker and reiterated its "underperform" rating, citing worries over the company's service fees.
McDonald's slumped after Cowen reduced its February comparable sales for the fast-food giant to below consensus.
Time Warner is in preliminary talks with potential buyers to sell some of its Time publishing assets. Shares were slightly higher following the news. CEO Jeff Bewkes said while has has no immediate plans, the company is exploring various options.
Comcast rallied after the company announced that it will buy General Electric's entire 49 percent common equity stake in NBCUniversal for approximately $16.7 billion. Comcast also increased its dividend by 20 percent and said will repurchase $2 billion in stock in 2013. GE, meanwhile, said the sale will allow it to return more cash to shareholders. GE's board increased the size of its share repurchase plan to $35 billion and said it plans to buy back about $10 billion in shares this year. Credit Suisse raised its rating on Comcast to "outperform" from "neutral" and increased its price target to $48 from $40.
In addition, Comcast reported earnings of 52 cents a share on revenue of $15.94 billion. (Read More: Comcast CEO: 'Bullish and Optimistic' About NBCU)
Also among earnings, Deere posted quarterly results that topped expectations and boosted its 2013 revenue forecast.
Cliffs Natural Resources plunged to lead the S&P 500 laggards after the coal company posted a quarterly loss and slashed its dividend by 76 percent. Rivals Alpha Natural Resources and Peabody Energy also traded lower.
Dean Foods posted better-than-expected earnings thanks to cost cuts. But shares slumped after the company said it has decided retain up to 19.9 percent of its WhiteWave dairy line, as analysts expressed skepticism about the future of the milk business amid volatile costs and intense price competition from store brands.
Merck edged lower after the pharmaceutical giant said it sees first-quarter earnings of between 76 cents a share and 78 cents a share, excluding one-time items, well below current Wall Street expectations of 86 cents a share, citing the impact of the Venezuelan government's intention to devalue its currency.
Network equipment maker and Dow component Cisco is slated to report earnings after the closing bell. Other notable companies scheduled to post results include WholeFoods, Applied Materials and MetLife.
Groupon soared after Stern Agee upgraded the daily-deal website to "buy" from "neutral."
On the economic front, retail sales eked out a gain in January as tax increases and rising gasoline prices held consumers back from spending, according to the Commerce Department. And import prices climbed in the same period, according to the Labor Department, gaining for the first time since October as fuel prices jumped. Export prices also logged a modest increase.
And business inventories edged up 0.1 percent, according to the Commerce Department.
Weekly mortgage applications fell last week, with purchase and refinance demand drying up as interest rates rose for the fourth week in a row, according to the Mortgage Bankers Association. (Read More: Mortgage Mess Still Mires Recovery)
Treasurys extended their losses after the government auctioned $24 billion in 10-year notes, at a high yield of 2.046 percent. The bid-to-cover ratio, an indicator of demand, was a weak 2.68, compared to a recent 10-auction average of 2.96.
"Auction performance has been volatile recently at the 10-year sector, with refunding month auctions tending to underperform," wrote Barclays analysts Ajay Rajadhyaksha and Dean Maki. "Foreign investor participation has declined steadily in the sector, but has been mostly offset by an increase in domestic fund participation. While the sector has not cheapened recently, the price action over the previous six auctions suggests that it has not needed a set-up."