Green Mountain Coffee Roasters Inc., the maker of Keurig one-cup brewing machines and coffee pods, fell the most in more than five weeks after Kroger Co. said it will sell private-label coffee pods for the devices.

Green Mountain declined 5.8 percent to $21.79 at 11:24 a.m. in New York, after falling as much as 9 percent for the biggest intraday loss since May 3. Kroger declined 0.3 percent to $21.50.

Kroger Co, the largest US operator of grocery stores, plans to sell its own version of the pods used in Green Mountain’s Keurig single-cup brewers later this year, Keith Dailey, a Kroger spokesman, said in an e-mail. Kroger may also make pods for other such brewers, he said.

Green Mountain, based in Waterbury, Vt., will face a growing private-label challenge from groceries when its K-Cup patents expire in September. Supervalu Inc. hasn’t ruled out making store-brand coffee pods after that date.