Traders on the floor of the New York Stock Exchange.

UPS —The shipping giant missed estimates by four cents , reporting second quarter profit of $1.21 per share, excluding certain items, though revenue did beat estimates. Revenue per package fell despite increased prices.

Pfizer –Pfizer earned 58 cents per share for the second quarter , excluding certain items, beating forecasts by one cent. Revenue was above Street forecasts, with the company saying its newly launched products are beginning to gain traction.

Merck –The drug maker beat estimates by four cents with second quarter profit of 85 cents per share, with revenue also above estimates. Merck was helped by strong sales of its newer drugs, helping to offset the loss of patent protection for its older offerings.

Aetna –The insurer reported quarterly profit of $1.69 per share, excluding certain items, beating estimates by nine cents. Revenue was also above consensus, and Aetna raised its full-year forecast as well on an increase in membership, among other factors.

Check out which companies are making headlines before the bell:

Nielsen Holdings–The media ratings service reported second quarter profit of 62 cents per share, excluding certain items, one cent above estimates. Nielsen said its results were driven by improvements in both retail and audience measurement, as well as a successful integration of Arbitron.

International Paper–The paper producer earned 95 cents per share for the second quarter, beating estimates by 12 cents, as it was able to expand profit margins during the quarter.

Sirius XM–The satellite radio operator matched estimates with second quarter profit of two cents per share, but revenue was above estimates as subscribership rose five percent. Sirius also raised its revenue forecast for the year.

McGraw-Hill Financial–The parent of Standard & Poor's earned $1.06 per share for the second quarter, excluding certain items, beating estimates by seven cents. Revenue was also above forecasts, as its ratings business grew thanks to an increase in bond offerings.

Waste Management–The environmental services company reported second quarter profit of 60 cents per share, excluding certain items, one cent above estimates, though revenue fell short. Separately, the company is selling its Wheelabrator Technologies unit to Energy Capital Affiliates for $1.94 billion in cash.

Eaton Corp–The hydraulic systems maker earned $1.11 per share for the second quarter, missing estimates by two cents. However, it did record strong results in its electrical and aerospace businesses.

Darden Restaurants–The restaurant chain announced the impending departure of CEO Clarence Otis, following efforts by major shareholder Starboard Value to institute changes at the restaurant operator. Starboard will have at least three seats on the Darden board, following the company's announcement that it would nominate a slate of nine directors for 12 available seats.

Herbalife–Herbalife reported second quarter profit of $1.55 per share, excluding certain items, missing estimates by one cent. Its revenue also missed estimates, and the nutritional supplement maker also cut its sales outlook for the year after having raised it three months ago.

Norwegian Cruise Line–The cruise line operator reported second quarter profit of 58 cents per share, excluding certain items, beating estimates by one cent, although revenue was well short of expectations.

Cognex–Cognex beat estimates by seven cents with second quarter profit of 29 cents per share, with revenue also above consensus. The maker of machine vision products also forecast higher than expected revenue for the current quarter, with improvements noted in several of its key markets.

Trulia–The real estate web site operator revealed the termination fees involved in its deal to be acquired by Zillow. The fees, determined by various circumstances, range from $69.8 million to $150 million.

McDonald's —The company's Japan unit withdrew its earnings guidance for 2014, following the shutdown of one of its major suppliers.

BP –The global oil giant reported a 36 percent rise in second quarter profit, but the oil producer also warned of possible impact from increasing Western sanctions on Russia. BP has a nearly 20 percent stake in Russia's state oil company Rosneft.

Aecom Technology–Aecom will reportedly announce the acquisition of stadium construction specialist Hunt Construction this morning, which would be the engineering company's second acquisition in two weeks. Aecom bought URS Corp. for $4 billion in cash and stock earlier this month.

—By CNBC's Peter Schacknow

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