SEATTLE — Amazon customers will soon be able to watch live football games as part of the retailer’s growing online video service.

The National Football League has reached an agreement with Amazon to allow Amazon Prime customers to stream 10 “Thursday Night Football” games in the coming season, NFL and Amazon representatives said. Prime customers spend $99 a year for a membership that includes free shipping and a video service with a library of movies and TV shows.

Amazon agreed to pay about $50 million for the streaming rights to the NFL games, according to a person briefed on the deal who asked for anonymity because the price was confidential. The amount was about five times the roughly $10 million Twitter agreed to pay the NFL last year for streaming rights to “Thursday Night Football,” this person said.

The agreement represents another step in the delicate dance between tech and entertainment companies as more viewers shift their viewing habits to the internet and digital devices. Amazon and Netflix are pouring money into their video services, both licensing content and producing original programming.

Some viewers of these video services are so-called cord cutters, who forgo cable television subscriptions. Sports remain a big reason people keep their cable services. But ratings wobbled last year for many NFL broadcasts, and the league has grown concerned that younger viewers are not watching football in traditional ways.

Agreements with Amazon and other internet companies are an attempt by the NFL to reach younger fans, even though the league risks alienating the broadcast networks that pay hundreds of millions of dollars in rights fees. For Amazon, the NFL agreement is an attempt to fill one of the biggest holes in its lineup.

Amazon will stream games produced by either CBS or NBC, which air the games on television. The Thursday night games will also air on NFL Network, the league’s cable channel.

The television audience for “Thursday Night Football” dwarfed the internet audience during last season’s experiment on Twitter. The average viewership on Twitter at any given minute was 266,000, according to the NFL. The figure for television, including broadcast and cable, was 15.8 million. Analysts estimate that as many as 60 million households use Amazon Prime.