LOS ANGELES — NBC and Fox are set to launch an advertising-supported online video site that hosts programming from varied entertainment companies in a bid to seize viewers from Google Inc.'s YouTube, the broadcasters said.

A test version of the site, Hulu.com, went online Monday to mostly favorable reviews and with plans to premiere a final version in a few months, company officials said.

The site, developed by News Corp. and NBC Universal, a unit of General Electric Co., offers free viewing of full-length films and TV episodes, supported by advertising.

It will host programming from the two networks, as well as TV shows and films from Sony Corp. and Metro-Goldwyn-Mayer Inc.

"Consumers identify with shows and films," rather than networks, Hulu chief executive Jason Kilar said. "When you aggregate great content together, it makes things easier for the user."

Hulu's debut comes amid tensions between entertainment companies and popular online video sites, such as YouTube, where unauthorized clips from shows often appear.

Viacom Inc., which owns Comedy Central, MTV, VH1 and many other cable channels, is suing YouTube for $1 billion, claiming massive copyright infringement of clips from popular shows, including "The Daily Show with Jon Stewart." YouTube has said it follows copyright laws by removing protected video upon request.

NBC Universal's CEO Jeff Zucker, speaking Monday in New York at an event sponsored by the S.I. Newhouse School of Public Communications at Syracuse University, said he didn't see Hulu as a direct competitor to YouTube, saying the two sites are "really two separate things."

Hulu will legally offer hundreds of episodes of current shows such as NBC's "30 Rock" and Fox's "The Simpsons," as well as older shows such as "Lou Grant" and "Lost in Space."

Its movie offerings will consist of films that have already been edited for television broadcast, which will contain short ads online in the places where they would appear on TV.

The shows will be available at Hulu.com, as well as on distribution partner Web sites such as AOL, MSN, MySpace, Yahoo and Comcast.