Google Inc.’s YouTube video website plans to add movie rentals from major studios including Sony Corp.’s Columbia Pictures and Comcast Corp.’s Universal Pictures, according to people with knowledge of the situation.

Sony has agreed to offer its films and Universal is discussing an accord with YouTube, said the people, who weren’t authorized to speak publicly. Warner Bros., a unit of Time Warner Inc., has also agreed to provide movies, according to TheWrap.com, which reported the developments on April 25.

Adding films from major studios would boost YouTube’s ability to compete for paying viewers against Apple Inc.’s ITunes, Amazon.com Inc. and other online outlets such as Best Buy and Wal-Mart Stores Inc.’s Vudu. YouTube now offers movies such as “3:10 to Yuma” from Lions Gate Entertainment Corp.

“We’ve steadily been adding more and more titles since launching movies for rent on YouTube over a year ago and now have thousands of titles available,” Google said in an e-mailed statement. “Outside of that, we don’t comment on rumor or speculation.”

Google, based in Mountain View, California, rose $7.77 yesterday in Nasdaq Stock Market trading. The shares have declined 10 percent this year.

News Corp.’s 20th Century Fox and Viacom Inc.’s Paramount Pictures aren’t involved, TheWrap and the New York Times reported. Walt Disney Co., which rents movies through Apple Inc.’s iTunes, is on the sidelines for now, the publications said.