Dunkin' to expand in the South

BostonBusiness: Dunkin Donuts' expansion in the Nashville market, with as many as 100 new locations planned over the next few years, is part of the chain's strategy to triple its stores nationwide to 15,000 by 2020. Dunkin' is the country's top doughnut chain. But under new owners, including two of Boston's biggest private-equity firms, the company is moving fast to capture the lucrative coffee market and broaden its concept to include hot dogs and pizza in new cities. Last year, nearly 70 percent of its 543 new U.S. stores were built outside the Northeast.