Dunkin’ Brands Group Inc., the Canton-based parent company of Dunkin’ Donuts and Baskin-Robbins, announced Friday that the previously announced underwritten public offering by certain of its stockholders of 21,754,659 shares of its common stock has been commenced by the underwriter to purchasers in one or more transactions on The Nasdaq Global Select Market.

“The selling stockholders will receive all of the net proceeds from this offering,” Dunkin’ Brands said in a press release. “No shares are being sold by the company.”

On Thursday, shares of company stock closed at $30.70, unchanged for the day.

Dunkin’ Brands had an initial public offering of stock just over a year ago. On the first day of trading, shares soared 46 percent above the initial public offering price.

In 2006, a group of private equity firms made up of Bain Capital Partners LLC, the Carlyle Group, and Thomas H. Lee Partners LP completed the acquisition of Dunkin’ Brands from Pernod Ricard SA for $2.43 billion.

At the end of the second quarter, Dunkin’ Brands and its franchisees operated more than 10,000 Dunkin’ Donuts restaurants and nearly 7,000 Baskin-Robbins restaurants. For the full-year 2011, the company had franchisee-reported sales of about $8.3 billion.