Serving as a third-party provider to retailers and supermarket chains is one part of a multi-faceted approach Amazon is taking to grow its grocery presence.

Three New Seasons stores are currently available for delivery orders on Amazon's website, a spokesperson for the grocer wrote in an email, noting that they "have been strategically selected to serve the majority of our customers in the Portland-metro area and southwest Washington."

Amazon plans to add more New Seasons locations for delivery "over time," Amazon's Head of U.S. Grocery Partnerships Christian Seitel said in the announcement. New Seasons Market has more than 20 stores in the greater Portland and Vancouver, Washington, areas.

Prime members can get free delivery on their first three orders from New Seasons Market.

In September, Amazon announced it started providing same-day grocery delivery service from four stores run by Seattle-area supermarket chain Metropolitan Market -- another Good Food Holdings banner. Amazon noted at the time that it plans to expand its delivery service to more Metropolitan Market locations.

Amazon has also provided delivery from Good Food Holdings' Bristol Farms chain, which operates in California, for several years.

Along with the three Good Food Holdings banners, Amazon provides delivery for East Coast chain Weis Markets, Arizona-based Cardenas Markets, Save Mart in California's Central Valley and San Francisco Bay Area supermarket chain Lucky Supermarkets.

Amazon's grocery efforts include growing the footprints of its Amazon Fresh and Whole Foods Market chains as well as rolling out digital tools, from a new grocery subscription to its expanding smart cart solution.

The Amazon tie-up expands New Seasons' list of e-commerce partners. New Seasons launched delivery through DoorDash in April, the announcement noted. The chain also provides delivery through Instacart.