Check out which companies are making headlines before the bell:
United Technologies—Chief Executive Officer Louis Chenevert is retiring effective immediately, and will be replaced by Chief Financial Officer Gregory Hayes.
Prosensa—The Dutch pharmaceutical company has agreed to be bought by BioMarin Pharmaceuticals for $17.75 per share in cash, or $680 million. The deal could be worth up to $840 million depending on certain Prosensa drugs gaining approval.
Aruba Networks—The provider of networking solutions said it inadvertently posted certain internal information on its website last week, and that the information was incomplete, unaudited, and not intended for external release.
Exxon Mobil and Chevron—Raymond James downgraded Exxon to "market perform" from "outperform," and cut its rating on Chevron to "outperform" from "strong buy." It expects Exxon to be a relative underperform in 2015, based on its defensive profile. It also considers Chevron a defensive stock, although the firm is still bullish on Chevron because of its track record on resource replacement.
Costco—Goldman removed the warehouse retailer's shares from its "conviction buy" list, noting a 19 percent run up since it was added to the list in late July. However, Goldman is still maintaining a "buy" rating.
Denny's—Janney upgraded the restaurant chain's stock to "buy" from "neutral," both on the strength of a restaurant remodeling and improvement overall in the family dining sector.
American Airlines Group—The airline and its pilots union agreed to keep talking on a new labor contract, delaying a plan to seek a deal through binding arbitration.
Tesla—CEO Elon Musk told German weekly Der Spiegel that the company is in talks with Germany's BMW on a possible collaboration involving batteries and other components.
Aviva—The company has agreed to an $8.8 billion stock swap merger with rival life insurer Friends Life, in a combination of two British insurance companies.
BHP Billiton—The mining company is ramping up its cost-cutting plans, as commodity prices tumble. BHP expects to save at least $4 billion by June of 2017, up from an earlier forecast of $3.5 billion.
Lockheed Martin—The advanced technology systems firm won a $4.7 billion Pentagon contract to supply a new batch of F-35 fighter jets.
Lionsgate—The studio saw its new film "The Hunger Games: Mockingjay Part I" top the weekend box office with North American ticket sales of $123 million, although that was 22 percent lower than sales for the prior "Hunger Games" movie.
Jacobs Engineering—CEO Craig Martin is retiring in late December due to health reasons. He'll be replaced on an interim basis by former CEO and current chairman Noel Watson.
Intel—The chip maker's shares could jump 30 percent over the next two years, according to an article in this weekend's Barron's.