A major movie studio will begin an experiment next week making feature films available for downloading over the Internet.

On Monday, Miramax will allow its 1999 release "Guinevere," starring Sarah Polley and Stephen Rea, to be downloaded for $3.49. It will take about 30 minutes to move over a high-speed Internet connection. The digital version of "Guinevere" will play on home computers full-screen in near-DVD quality. But there's a catch: The downloaded movie expires in 24 hours, and cannot be played on your computer after that. If you e-mail a copy to a friend or transfer it to another device, it will not play at all. Studios are struggling to develop an Internet movie strategy, hoping to have workable alternatives available before a Napster-like Web site makes swapping pirated films as easy as downloading the latest Britney Spears ballad. Their earlier experiments with producing original short films and animation for the Internet failed, leaving studios wondering how to use Net technology while protecting their copyrights. "Guinevere" will be available for download at www.miramax.com, www.sightsound.com and www.guineverethemovie.com. Miramax, a division of the Walt Disney Co., signed a deal in April with SightSound.com to offer 12 feature films on the Web. The arrangement is an experiment in consumers' willingness to watch downloaded films on a pay-per-view basis. Other studios have been exploring a video-on-demand strategy, making movies available over high-speed cable television lines or over private networks.