Check out which companies are making headlines before the bell:
Darden Restaurants — The Olive Garden parent reported adjusted quarterly profit of $1.21 per share, 2 cents a share above estimates, with revenue also above forecasts. Darden's same-restaurant sales rose 6.2 percent during the quarter.
Walgreens Boots Alliance — The drugstore chain operator beat forecasts by 3 cents a share, with adjusted quarterly profit of $1.31 per share. Revenue did miss estimates as Walgreens navigates a "challenging retail sales environment," but it said it is making progress in cutting costs and implementing other efficiencies.
Twitter — Twitter has won the online streaming rights to Thursday night National Football League games, according to a Bloomberg report.
Walt Disney — Chief Operating Officer Tom Staggs is departing the company. He had been seen as a likely successor to CEO Robert Iger, but is said to have made his decision after learning that Disney's board had decided to broaden a search for Iger's successor to include more candidates.
AT&T — Macquarie began coverage on the telecommunications company with an "outperform" rating, noting that AT&T is likely to achieve above-GDP growth over the next few years.
Starbucks — Starbucks is rated "buy" in new coverage at Evercore, pointing to the consistency of store growth and earnings. The firm thinks the coffee chain can grow earnings at 17 percent annually through 2020.
Wendy's — Evercore began coverage on the restaurant chain with a "buy" rating, saying its streamlining effort has made substantial progress.
Constellation Brands — Wells Fargo rates the spirits maker "outperform" in new coverage, saying it is positioned to be a leading consumer staples company for years to come.
Tesla Motors — Tesla sold 14,820 vehicles during the first quarter, up 50 percent from a year earlier but a lower number than had been expected. The automaker's output was slowed in part by supplier shortages and what Tesla called its own "hubris in adding far too much new technology to the Model X."
Allergan — Allergan shares are under heavy pressure, following the announcement of new anti-inversion deal rules from the Treasury Department that could endanger its pending $160 million merger with Pfizer. For its part, Pfizer said it was reviewing the Treasury's actions and added that it would not speculate on any potential impact on the combination of the two drug makers.
United Continental — The airline reached a tentative five-year labor deal with 30,000 members of its machinists union. Workers will get a roughly 30 percent pay raise over the length of the contract, plus other benefits.
Valeant Pharmaceuticals — Valeant will cut the sales force for the female sexual dysfunction drug Addyi, as well as some dermatology products, according to a Reuters report which quotes an internal memo.
Dave & Buster's — The entertainment and arcade chain launched a 3.4 million share secondary offering on behalf of shareholder Oak Hill, according to a StreetAccount report.
Sprint — The mobile carrier struck a deal with Amazon which will allow customers to add the Amazon Prime service for an extra $10.99 per month. That adds up to more than Amazon Prime's $99 annual fee, but also allows customers the chance to stay or leave one month at a time.
Willis Towers Watson — The consulting firm now has Valueact Capital as a 5.9 percent stakeholder, according to a Securities and Exchange Commission filing. Valueact considers the shares undervalued and plans to have conversations with management about how to enhance shareholder value.