Amazon is extending the benefits of a Prime subscription to online stores beyond its own site, a move geared toward boosting revenue from merchant fees and expanding its logistics footprint.

The company said Thursday the new service it calls “Buy with Prime,” will initially be available by invitation for merchants who ship their products using Amazon’s warehouse and delivery services. Then, it will be rolled out for merchants who don’t sell on Amazon or use its delivery services.

Amazon.com Inc. said the service will only be available for U.S. customers. Launched in 2005, Prime has more than 200 million members worldwide who pay $139 a year, or $14.99 a month, for faster shipping and other perks, such as free delivery and returns.

The company said Prime members using “Buy with Prime” would be able to see the Prime logo on eligible products on a merchant’s site and make purchases using the payment and shipping information stored in their Amazon account.

Merchants who use the service will pay various fees, which the retailer says are calculated depending on what sellers use. “With no fixed subscription fee or long-term contract required, merchants can expand selection or cancel at any time,” it said.