Green Mountain Coffee Roasters fell two percent to $40.95 Tuesday after the Vermont-based company said it entered a partnership with Dunkin' Donuts.

Green Mountain said it will make Dunkin' Donuts coffee available for use in its Keurig single-cup coffee brewers.

Dunkin' Donuts coffee will be packaged in Green Mountain's K-Cup portion packs and be sold in 14-count boxes at Dunkin' Donuts stores in the US and Canada.

Financial terms of the deal were not disclosed.

The partnership escalates the battle between Green Mountain, Starbucks and others for the single-cup coffee market, which is currently dominated by Green Mountain.