Dell agreed to be taken private in a $24.4 billion buyout deal by a consortium led by founder Michael Dell, ending the computer maker's 25-year history as a publicly traded firm. Dell shareholders will receive $13.65 a share. Shares fluctuated for most of the day but finished slightly lower. The deal marks the biggest leveraged buyout since the 2008 financial crisis.
US Stocks Look 'Very Favorable': Goldman's O'Neill
Among earnings, Yum Brands beat earnings forecasts for the fourth quarter, but shares fell after the parent company of KFC and Pizza Hut said same-store sales in its China division fell 6 percent and it now expects to post a mid-single digit earnings decline for 2013 from the prior year. At least three brokerages cut their price target on the company.
Kellogg edged higher after the cereal maker reported a narrower-than-expected quarterly loss, thanks to improvements in Latin America and stood by its full-year forecast.
BP gained after the British oil company topped earnings expectations, thanks to a strong performance from its refining division. The company also expects four new major upstream projects to begin production by the end of 2013.
Computer Sciences soared to lead the S&P 500 gainers after the tech company blew past earnings expectations.
And Archer Daniels Midland rose after the agribusiness giant posted higher earnings, helped by strong global demand for oilseeds.
Disney, Chipotle Mexican Grill, Panera Bread and Zynga are among notable companies scheduled to post earnings after the closing bell. (Read More: Disney Earnings Preview: All Eyes on ESPN and Theme Parks)
So far, 278 S&P 500 firms have reported quarterly results, with 69 percent topping earnings expectations, while 65 percent have exceeded revenue estimates, according to Thomson Reuters. If all remaining companies post quarterly results that match forecasts, earnings will be up 4.5 percent from last year's fourth quarter.
Boeing advanced after the Dow component formally filed a request with the FAA to allow test flights of 787 Dreamliners to resume.
McGraw-Hill tumbled to lead the S&P 500 laggards for a second session after the U.S. government launched a civil suit against ratings agency Standard & Poor's for wrongdoing in its rating of mortgage bonds prior to the 2008 financial crisis. Moody's also ended sharply lower.
Barnes & Noble shot higher after investor Daniel Tisch raised his stake in the bookstore chain to 8.1 percent, according to a regulatory filing. Tisch is currently the company's second largest shareholder after chairman and founder Leonard Riggio.
European shares finished higher as investor confidence was boosted by a series of earnings releases and positive business activity data released in the euro zone.
On the economic front, the services sector grew to 55.2 in January, according to the Institute for Supply Management's non-manufacturing index. The reading was in line with expectations according to a Reuters poll, but slightly down from 55.7 in December. Still, a reading above 50 indicates a sector expansion.