Check out the companies making headlines before the bell:

Lennar — The homebuilder fell a penny a share short of estimates, with quarterly earnings of 74 cents per share. Revenue also missed forecasts, despite a 24 percent jump in new orders and a 30 percent increase in deliveries.

WellCare Health Plans — WellCare agreed to be bought by rival health insurer Centene in a cash-and-stock deal valued at $305.39 per share. WellCare shareholders will get $120 a share and 3.38 Centene shares for each share they now hold.

Boeing — A 737 MAX jet operated by Southwest Airlines made an emergency landing in Orlando due to an engine issue. The jet only had two crew members aboard and Southwest said the issue was not related to the computer system that has grounded the jet for passenger service worldwide following two fatal crashes. Separately, Citi resumed coverage of Boeing with a "buy" rating, based on a multi-month grounding of the 737 MAX aircraft with a "manageable fix."

Southwest Airlines — The airline cut its first-quarter forecast for REVPAR (revenue per available seat mile) due to the grounding of its 737 MAX jet fleet. Southwest is the first carrier to report on impact on its earnings from the removal of the Boeing jets from service.

KB Home — KB Home reported quarterly profit of 31 cents per share, 5 cents a share above estimates. The homebuilder's revenue fell short of Street forecasts due to a decline in average selling prices. KB Home did swing to a profit from a year-earlier loss during the quarter.

Fiat Chrysler — Fiat Chrysler could be an eventual takeover target of French automaker Renault, according to the Financial Times. The paper said Renault wants to restart merger talks with longtime partner Nissan, and then set its sights on a bid to buy Fiat Chrysler.

J.C. Penney — J.C. Penney named former Vitamin Shoppe Chief Financial Officer Bill Wafford as its new chief financial officer, effective April 8. Former CFO Jeffrey Davis had left the retailer in October.

Novartis — The drugmaker won Food and Drug Administration approval for its new multiple sclerosis drug Mayzent, designed for patients whose attacks have shifted from intermittent to more frequent.

Amazon.com — Amazon and Volkswagen have formed a strategic partnership to create an "industry cloud" for automakers, according to a German newspaper. The report said more details will be announced soon.

Apple — Apple won a ruling from the International Trade Commission (ITC) late Tuesday in its long-running patent battle against chipmaker Qualcomm. Earlier in the day, in a separate patent ruling, the ITC ruled in favor of Qualcomm.

Shoe Carnival — Shoe Carnival reported adjusted quarterly profit of 11 cents per share, beating estimates by 5 cents a share. Revenue also came in above analysts' forecasts. Same-store sales rose 4.7 percent during the quarter.

DowDupont — DowDupont spin-off Dow Inc. will replace DowDupont in the Dow Jones Industrial Average when the chemical maker splits into three separate publicly traded companies next week.

Papa John's — Stifel Nicolaus upgraded the pizza chain's stock to "hold" from "sell," saying investors now believe the worst is behind Papa John's and that they are willing to give the company time to execute its sales plan.

Ralph Lauren — Wells Fargo upgraded the apparel retailer to "outperform" from "market perform," saying it likes the company's prospects for accelerating its growth.