LOS ANGELES (Hollywood Reporter) - Exactly a year after it was launched in the United States, the Sony PlayStation Portable's days as a hand-held movie-viewing device might be numbered.

Disappointing sales have slowed the flow of movies on the proprietary Universal Media Disc to a mere trickle. At least two major studios have completely stopped releasing movies on UMD, while others are either toying with the idea or drastically cutting back.

And retailers also are cutting the amount of shelf space they've been devoting to UMD movies, amid talk that Wal-Mart is about to dump the category entirely.

Wal-Mart representative Jolanda Stewart declined comment on reports that the retailer is getting out of the UMD business. But studio sources say such a move is imminent, and a check Wednesday of a Wal-Mart store in Santa Ana, Calif., revealed a drastic shrinkage of UMD inventory. Several shelves of movies in the PSP section were gone; all that remained were seven UMD titles sitting bookshelf-style on the top of the PSP section, with no prices or other information.

Universal Studios Home Entertainment has completely stopped producing UMD movies, according to executives who asked not to be identified by name. Said one high-ranking exec: "It's awful. Sales are near zilch. It's another Sony bomb -- like Blu-ray."