Check out which companies are making headlines before the bell on Monday:
Caterpillar - Caterpillar earned $1.31 per share for the first quarter, nine cents below estimates, with revenue falling short, as well. The company's revised 2013 outlook for revenue and earnings is also below estimates, with CEO Doug Oberhelman calling the first quarter "challenging" because of inventory issues, among other things.
Halliburton - The oilfield services company earned $0.67 per share for the first quarter, excluding certain items, 10 cents above estimates. Halliburton saw increased international business offset weakness in the North American market. The company also said it's moving towards settling litigation relating to the 2010 Macondo well explosion and oil spill.
Hasbro - The toymaker earned $0.05 per share, excluding certain items, one cent above estimates, with revenue improving in three of its four product categories.
(Read More: See the Day's Top Percentage Winners & Losers)
General Electric - JPMorgan Chase has downgraded GE to "neutral" from "overweight," while lowering the price target to $22 from $24 a share. The firm cited smaller profit margins and slower growth for the industrial giant.
Verizon Communications - Macquarie has downgraded Verizon to "neutral" from "outperform," saying that it still likes the management team and the company's execution, but pointing to an impending slowdown in wireless revenue growth.
Power-One - The California-based solar products maker will be bought by Swiss industrial group ABB for $6.36 per share in cash, or about $1 billion total. Power-One is one of the world's biggest maker of solar inverters. The deal represents a 57 percent premium for Power-One shareholders over Friday's closing price.
Boeing - The jetmaker could receive formal Federal Aviation Administration approval this week to return its grounded 787 jet to service. Regulators gave their OK on Friday to a redesign of the jet's battery system.
Elan - The drugmaker has rejected a takeover bid from U.S. investment firm Royalty Pharma, with the drugmaker's board saying the $11.25 per share bid "grossly undervalues" the company.
Apple - Apple may push back the release date of its next iPhone, according to Reuters, because of design issues involving a fingerprint sensor. Separately, Forbes reports that some executives inside Apple are seeking to have CEO Tim Cook replaced.
Amazon.com, eBay - The Senate is likely to vote today on ending debate over a bill requiring Internet retailers to collect sales tax on all purchases. That could mean the bill will come to a vote later this week.
(Read More: eBay Starts Massive Push Against Sales Tax)
International Business Machines - IBM shares remain on watch today after the stock posted its biggest one-day percentage drop in nearly three years Friday. That followed quarterly earnings that fell short of Street estimates.
Hess - Barclays has upgraded Hess shares to "overweight" from "equalweight."
(Read More: See CNBC's Market Insider Blog)
—By CNBC's Peter Schacknow
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