Check out the companies making the headlines after the bell on Monday:
Shares of Hershey fell more than 11 percent after hours after Mondelez announced that it has ended discussions of a possible merger with Hershey, a combination that would have created a global powerhouse selling some of the world's best known chocolates and snacks.
In a statement, Mondelez CEO Irene Rosenfeld said the company decided "there is no actionable path forward toward an agreement" following additional discussions.
Shares of United Continental Holdings gained more than 1 percent after hours, while shares of American Airlines fell more than 1 percent.
American Airlines President J. Scott Kirby will leave the company and take the same role at United Continental, the companies said.
American said Kirby is leaving the airline effective immediately. In a letter to United employees, CEO Oscar Munoz said he appointed Kirby as president of the company, a newly created position.
Shares of ScanSource fell more than 11 percent following the company's fourth quarter earnings and revenue miss.
The technology company reported fourth-quarter earnings of 51 cents per share on revenue of $877.5 million. Analysts expected earnings of 71 cents per share on revenue of $886.2 million, according to a Thomson Reuters consensus estimate.
Shares of Catalent slid more than 4 percent after hours following the company's fourth-quarter earnings miss, and revenue beat.
The company reported fourth-quarter earnings of 52 cents per share on revenue of $532.2 million, compared to analysts' expectations of 53 cents per share on revenue of $502.3 million, according to a Thomson Reuters consensus estimate.
— The Associated Press and CNBC's Christine Wang contributed to this report.