United Natural Foods Inc., the company that acquired Supervalu Inc. last year, is selling a portion of the Shoppers Food & Pharmacy chain that Supervalu owned and operated on the East Coast.

UNFI said Friday it will sell 13 of 43 Shoppers stores to three separate grocery operators. Four more locations will close by the end of January, leaving UNFI with 26 other Shoppers locations to sell or close.

The company is also trying to sell Supervalu's bigger retail unit, Cub Foods, the largest grocery chain in Minnesota.

A spokesman on Friday said that the firm continues to "make progress" on selling Cub but hasn't updated its timeline. Executives in October said that Cub, which has 79 stores, will be sold next year.

The 17 Shoppers stores that are closing or being sold are in Maryland and Virginia. Shoppers Food will start closing sales at the 17 stores and those purchased will eventually reopen under the new owners' banners. The buyers asked not to be identified but will make announcements of their own soon, a Supervalu spokesman said.

"Today's announcement reflects progress on our commitment to reduce UNFI's retail footprint and marks another step toward transforming UNFI into North America's premier food wholesaler," Steven Spinner, UNFI's chief executive, said in a statement. "We believe that exiting the retail business will further accelerate our business transformation and allow us to more appropriately allocate resources toward long-term growth initiatives."

Spinner and other UNFI executives are expected to discuss details about the sale of Cub and Shoppers when the firm releases quarterly results next week.

UNFI was the nation's leading wholesaler to the Whole Foods chain and other groceries that specialized in organic and natural foods. With its $2.9 billion purchase of Supervalu, the company picked up a leading distributor to traditional grocery stores.