Among the companies with shares expected to actively trade in Monday's session are Ann Inc. (ANN), Burger King Worldwide Inc. (BKW) and Tim Hortons Inc. (THI).

Activist investor Engine Capital LP pressed the women's apparel retailer Ann Inc. to pursue a sale, suggesting a strategic or private-equity buyer would be willing to pay between $50 and $55 a share, a big premium. Shares rose 3.1% to $38.70 premarket.

Burger King Worldwide Inc. is in talks to buy Canadian coffee-and-doughnut chain Tim Hortons Inc., a deal that would be structured as a so-called tax inversion and would move the hamburger seller's base to Canada. Burger King surged 12% to $30.43 premarket, while Tim Hortons climbed 15% to $72.

Industrial packaging company Greif Inc. (GEF) cut its expectations for the year, pointing to higher overhead costs and slightly lower-than-expected results from operations. Shares dropped 12% to $44.05 premarket.

Insys Therapeutics Inc. (INSY) said the U.S. Food and Drug Administration has granted orphan drug designation to its pharmaceutical cannabidiol for the treatment of glioblastoma multiforme, the most common and most aggressive malignant primary brain tumor in humans. Shares rose 5.5% to $37.49 premarket.

San Francisco-based InterMune Inc. (ITMN) agreed to be purchased by Roche Holding AG for $8.3 billion in cash, the biggest acquisition in years for the Swiss pharmaceutical giant after a string of much smaller purchases. Shares surged 36% to $73.29 premarket.

Chinese Internet company Qihoo 360 Technology Co. (QIHU) posted stronger-than-expected second quarter earnings, but the company, know as an antivirus provider, reported its gross profit margins declined two points from the first quarter amid heavy marketing expenses and personnel costs. Shares dropped 4.2% to $97.50 premarket.

Regado Biosciences Inc. (RGDO) said it terminated the late-stage trial testing of Revolixys, citing its lead program's efficacy in fighting coronary artery disease. The company said the study's data and safety monitoring board "indicated that the level of serious allergic adverse events associated with Revolixys was of a frequency and severity such that they recommended that we do not enroll any further patients in the Regulate-PCI trial." Shares dropped 49% to $1.45 premarket.

 
   Barron's Watch List: 

Barbie is having a rough year, and it's not because little girls have stopped wanting toys. My Little Pony, for example, is galloping off the shelves. It's made by Hasbro Inc. (HAS), which is the No. 2 U.S. toy company and is gaining on leader Mattel Inc. (MAT). Over the past year, Hasbro shares are up 16%, while those of Mattel have lost as much. Investors should stick with what's working. Look for Hasbro shares to return 20% over the next year, including a 3.3% dividend yield. Wait for improvement at Mattel.

The controversial Keystone XL pipeline, which would transport oil from Alberta to refineries in the U.S. Midwest and Gulf Coast, has been held up for four years by political and environmental red tape. But that hasn't slowed the growth of TransCanada Corp. (TRP), one of North America's largest energy-pipeline companies. Often overlooked by U.S. investors, TransCanada is an attractive alternative to the overheated U.S. pipeline master-limited-partnership sector.

Write to Lauren Pollock at lauren.pollock@wsj.com

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