Check out which companies are making headlines before the bell:
Comcast–The NBCUniversal parent earned 81 cents per share for the first quarter, seven cents above estimates, with revenue also above forecasts. Comcast also added $2.5 billion to its existing stock buyback program.
Cablevision–The cable operator reported adjusted quarterly profit of 20 cents per share, three cents above estimates, with revenue also above forecasts. Cablevision also saw growth in revenue per customer, as well as other metrics.
Tyson Foods–Tyson beat estimates by three cents with quarterly profit of 75 cents per share. Revenue was essentially in line, with Tyson's results helped by its acquisition of Hillshire Brands.
Berkshire Hathaway– Berkshire is on our watch list, following the company's annual meeting in Omaha over the weekend and its latest earnings report. Berkshire beat estimates and saw a 20 percent increase in operating earnings, thanks to higher revenue at its insurance and railroad operations.
McDonald's –McDonald's will unveil a turnaround plan this morning, as the restaurant chain seeks to revive flagging sales.
PartnerRe–The reinsurer has rejected a takeover offer from Italy's EXOR that was worth $130 per share, deciding to go ahead with its planned merger with AXIS Capital. It's also announced enhanced merger terms for the latter deal that will include a special dividend of $11.50 per share for PartnerRe shareholders.
Goldman Sachs–Goldman is in talks to sell its coal mines in Colombia, according to Dow Jones.
Twitter—Twitter plans to launch autoplay video by the end of June, according to a report in Adweek. Separately, Stifel upgraded Twitter shares to "hold" from "sell", although it said it maintains its view that Twitter is mispriced relative to its growth prospects.
Time Warner Cable–Time Warner Cable remains on watch, will be a stock to watch this week, as talks between Charter Communications and TWC about a possible deal take place. CNBC's David Faber reported last week that the two sides would be talking sometime this week.
American Express–American Express unveils a new rewards program called Plenti today. Its users do not have to be American Express members, and there's no cost to join.
Dean Foods–Dean Foods will unveil its new Dairy Pure milk product today, an effort to boost its milk sales.