Amazon US unveiled its Unbox Video Store yesterday, a direct rival to Apple's anticipated entry to the market, which allows US users to buy or rent TV shows, movies and other video content from the internet.

Amazon Unbox is offering thousands of DVD-quality videos from over 30 movie and TV studios, which can be stored on up to two PCs and two portable video players at once, the company said. When a user downloads a movie or show, Unbox automatically sends a second download file optimised for Windows Media-compatible portable devices. It also keeps track of media purchases on a personal page at Amazon's Your Media Library, and acts as a backup, allowing users to download video purchases onto an additional PC.

Unbox is one of many new services aimed at capturing the growing interest in downloading video from the internet. The service will compete with similar video download stores already in operation.

Unbox is charging between $7.99 and $14.99 for most movies, and rentals of the latest movies for $3.99.

Videos can also be sent as a gift. The company's Unbox RemoteLoad technology enables users to buy video from one PC, such as their home computer, and download it to another, Amazon said.

Major movie studios signed up with Unbox include Universal Pictures, Sony Pictures and Warner Bros Entertainment.

The service only works on Windows XP.