Amazon.com Inc. is planning to start a service that would let people store music and video online and access it from various digital devices, people familiar with the matter said. The company could announce the effort as early as Tuesday, the people said.

Amazon is still working out key legal issues related to the service, these people added. Most notably, Amazon has yet to secure content licenses from at least some major record labels and movie studios.

One major music company, Sony Corp.’s Sony Music Entertainment, expressed dismay at Amazon’s plans, echoing concerns of others in the industry. “We are disappointed that the locker service that Amazon is proposing is unlicensed by Sony Music,” a spokeswoman said Tuesday evening.

An Amazon spokesman didn’t respond to requests for comment.

Amazon executives have told several media companies that they are likely to seek licenses after this week’s expected announcement.

The online retailer appears to be racing Apple Inc. and Google Inc., both of which are also working on similar offerings, known as “locker” or “cloud” services.

Such services create an online music or video collection identical to the one on a user’s computer hard drive, then let the user access the collection from elsewhere.

Amazon has indicated to some outside executives that its new service could allow users to upload personal video. Amazon already gives people access to movies and television shows they buy from its digital-download service.

It was unclear Monday what kind of controls Amazon would put in place to distinguish actual personal video footage from movies “ripped” from DVDs without permission.

Online technology-news website CNET earlier reported on Amazon’s plans.

People in the media business have said that under certain conditions, Amazon may be able to offer some kind of locker without obtaining additional licenses beyond those they already have for their digital-download store.

However, such a system would likely need to be very basic. For instance, it might not be possible to let users access their collections from smartphones or other mobile devices.

Announcing a service before a company has such deals in place can cause headaches for technology companies. Google began touting a music service in May of last year but even after months of negotiations with major record labels, the company’s Google Music service has yet to materialize, along with many of the licenses that would be required to launch it.