Business briefs

North Chicago-based Abbott Laboratories said it is being investigated by the U.S. Justice Department over "sales and marketing activities" for Depakote, its third- biggest-selling drug. The investigation, in Virginia, includes a look at whether anti-kickback laws were violated in Medicare and Medicaid payments for the medicine, the company said Friday in a regulatory filing. Depakote, used to treat bipolar mania and epilepsy, brought in $1.36 billion in 2008 sales for Abbott Park-based Abbott. That was down 13 percent from the previous year, hurt by increased generic competition. "We are cooperating with the investigation," Abbott spokeswoman Adelle Infante said.

Borders Group will close five of its Waldenbooks stores in Chicago's suburbs in January as part of a national cutback in the small-format Waldenbooks chain. The stores slated to close are expected to start clearance sales in mid-December. They are at Fox Valley Mall in Aurora, River Oaks Center in Calumet City, Gurnee Mills in Gurnee, Lincolnwood Town Center in Lincolnwood, and at Louis Joliet Mall in Joliet. Nationwide, the closings of 200 Waldenbooks and Borders Express stores will mean that 1,500 workers, mostly part-time, will lose their jobs. Gift cards will be valid as long as the stores remain open, and at Borders stores and Borders.com.

Motorola started selling its "Droid" smart phone Friday at Verizon Wireless stores, and separately announced it had settled a patent dispute with Aruba Networks that ended in a cross-licensing agreement involving a technology used in wireless networks. Aruba will pay Motorola $19.8 million to resolve the patent lawsuit. The Schaumburg-based cellular-phone manufacturer has introduced Android OS smart phones "Cliq" and "Droid" for the holidays as the beginning of its plan to reverse the company's declining share of the wireless-phone market. Motorola boasted 20 percent of the global mobile-handset market a few years ago; that share is now 5.5 percent.