Check out which companies are making headlines before the bell:
Halliburton, Baker Hughes —- The two oilfield services giants called off their planned $28 billion merger after running into strong opposition from regulators who had said the deal would hurt competition. Halliburton will pay a $3.5 billion breakup fee to Baker Hughes as a result of the deal's termination, with Baker Hughes saying it will use the money to buy back stock and reduce debt.
Berkshire Hathaway — Berkshire won't be out with its quarterly numbers until Friday, but said at its annual meeting over the weekend that operating profit likely fell 12 percent, hurt by results at railroad operator BNSF.
Yahoo — Yahoo CEO Marissa Mayer would get a $55 million severance package if she is ousted as a result of the company's possible sale of its internet assets, according to a Securities and Exchange Commission filing.
IntercontinentalExchange — The New York Stock Exchange parent may get more time to consider a bid for the London Stock Exchange (LSE). Reuters reports that LSE's parent company may delay its shareholder meeting to approve its planned takeover by Deutsche Boerse until after the "Brexit" referendum on June 23.
J.C. Penney — J.C. Penney shares could double over the next three years, according to a Barron's article, which said the retailer has made substantial progress in improving its operations over the past year.
Facebook — Facebook is the target of a proposed class action lawsuit filed by a shareholder over the company's plan to issue a new Class C stock. The suit contends that the move is unfair and designed to give CEO Mark Zuckerberg even more power, with the new class not having any voting rights.
Apollo Education Group — Private equity firm Apollo Global Management raise its takeover bid for the University of Phoenix online college operator to $10.50 per share from its original $10, boosting the deal's value to $1.14 billion. The move is designed to win support from shareholders who had balked at the price of the original deal.
AIG — The insurance company raised $1.25 billion by selling a chunk of its stake in China insurer PICC, according to IFR. AIG first invested in PICC when it went public back in 2003.
Starz — The cable channel operator was upgraded to "outperform" from "underperform" at CLSA, which cites stabilizing revenue trends and long-term visibility into programming costs, among other factors.