Among the companies with shares expected to actively trade in Monday's session are Elan Corp. PLC (ELN, DRX.DB), Saks Inc. (SKS) and solar companies.

Drug maker Perrigo Co. (PRGO) agreed to buy Irish biotech firm Elan for $8.6 billion in the latest pharmaceutical-industry deal motivated at least in part by taxes. Perrigo will use a mix of cash and stock to buy Elan for $16.50 a share, a 10.5% premium over Elan's closing stock price Friday. Elan's American depositary shares rose 6.5% to $15.90 premarket.

Retailer Saks agreed to be bought by Hudson's Bay Co. (HBC.T) for about $2.8 billion in a purchase that is probably as much about high-end real estate as luxury clothes. Both boards approved the deal, which is worth about $2.9 billion, including the assumption of debt. Hudson's Bay agreed to pay $16 a share for Saks, a 4.5% premium to Friday's close. Saks shares rose 3.7% to $15.87 premarket.

Shares of Chinese solar companies rose premarket following a weekend deal between the European Union and China on solar-panel imports. Saturday's agreement, which sets a price floor for Chinese solar panel exporters, comes as the EU was about to slap import tariffs of nearly 48% on China's solar-energy exports starting on Aug. 6. Hanwha SolarOne Co.'s (HSOL) American depositary shares rose 11% to $3.83 premarket, while ReneSola Ltd.'s (SOL) ADSs rose 10% to $4.73, Yingli Green Energy Holding Co. (YGE) rose 9.5% to $4.38 and JinkoSolar Holding Co. (JKS) rose 8.1% to $13.93.

Chelsea Therapeutics International Ltd. (CHTP) said the U.S. Food and Drug Administration identified certain technical deficiencies in the company's resubmitted new drug application for its lead investigational drug candidate Northera. Shares fell 7.8% to $2.83 premarket.

Novavax Inc. (NVAX) said its virus-like particle vaccine candidate showed positive results in a preclinical test to protect against the deadly new A(H7N9) bird-flu strain. Shares rose 6.4% to $2.65 premarket.

Publicis Groupe SA (PUB.FR, PUBGY) and Omnicom Group Inc. (OMC) said Sunday they will merge to create a $35.1 billion advertising giant by market capitalization, overtaking current market leader WPP PLC (WPPGY, WPP.LN) in the industry's biggest deal ever. The companies said they will create a new entity called the Publicis Omnicom Group in a merger of equals. Omnicom shares were up 6.6% to $69.40 premarket.

 
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Oil and gas transporter Boardwalk Pipeline Partners LP's (BWP) second-quarter earnings rose 8.3%, but margins shrank amid weaker transportation revenue.

Carl Icahn on Monday countered recent comments made by Dell Inc. (DELL) founder Michael Dell about voter turnout and counting, the latest salvo in a protracted back and forth between the activist investor and the PC maker ahead of an impending vote on whether Dell should be taken private.

Intersil Corp. (ISIL) unveiled plans to cut about 10% of its workforce as the chip maker looks to further reduce costs. The company, which designs and makes analog semiconductors, also reported better-than-expected revenue for the second quarter.

Loews Corp. (L) on Monday said its second-quarter earnings surged sharply, as a 17% profit jump in its CNA Financial Corp. (CNA) insurance unit trumped a weaker performance at Diamond Offshore Drilling Inc. (DO).

Spectra Energy Corp. (SE) and NextEra Energy Inc. (NEE) will build a $3 billion pipeline bringing natural gas to power utilities in Florida, the companies said Friday, connecting the state to the natural-gas supply boom outside its borders.

Wynn Resorts Ltd.'s (WYNN) second-quarter profit fell 6% as the casino operator reported a $26.6 million charge on the early retirement of debt, masking an increase in revenue.

Write to Anna Prior at anna.prior@dowjones.com

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