Rivals Agree to Combine Standard for HDTV Systems : Technology: The competing development groups will pool their talents to bring products to market in 3 to 5 years.

Rival groups announced Monday that they would work together to develop a high-definition television system that would be available to consumers within three to five years and priced $1,000 to $2,000 more than conventional TV sets.

The breakthrough, which was reported in last Friday’s Los Angeles Times, follows three months of heated negotiations among the three HDTV development groups and a successful eleventh-hour effort by the industry to ensure that the HDTV standard would be compatible with computers.

Last week, the nation’s biggest computer companies threatened to break ranks from the group if the government didn’t endorse an HDTV standard that would allow information to be easily exchanged between computers and HDTVs. The computer industry said that such a capability will be crucial as computer, telephone and television technologies continue to merge into multimedia systems.

“They felt it made sense to combine the best elements of all the systems . . . to expedite the adoption of a new broadcast system compatible with computers,” said Richard E. Wiley, chairman of the HDTV Advisory Committee, which is evaluating HDTV technology for the Federal Communications Commission.

“We have a long way to go, but this is the end of the competitive phase,” Wiley said at a news conference.

High-definition TVs will provide much sharper video images and compact-disc quality sound, thanks to bigger TV screens that will be ideal for displaying the flood of entertainment and data that a growing number of cable programmers and information suppliers plan to offer consumers.

Representatives from the HDTV development groups said they will pool their talents to develop a “progressive scan” broadcast picture that utilizes “square pixels”--a term that describes the individual dots that make up a picture--to ensure compatibility with computers.

The HDTV officials said they will also attempt to design a technology that could support multiple transmission formats so that consumers could get better TV pictures as technology improves. Once HDTV sets are introduced, the current broadcast system would be phased out over a 15-year period, FCC officials have said.

It is unclear whether the joint HDTV effort would raise antitrust concerns with the federal government. Justice Department officials could not be reached for comment.

For the U.S. economy, HDTV holds the promise of a comeback in consumer electronics, since Japanese HDTV technology is already obsolete. Studies have estimated that HDTV could create as many as 100,000 U.S. manufacturing jobs. In addition, the nation’s 1,600 TV stations will spend more than $1 million each to prepare their transmitters and studio equipment for HDTV broadcasts.

Since the advisory committee had narrowed the field of HDTV systems from the initial 23 in the mid-1980s, three groups had been among the finalists competing for government approval of their HDTV technologies: General Instruments Corp. and the Massachusetts Institute of Technology; Zenith Electronics Corp. and AT&T;, and a consortium made up of Philips Electronics of the Netherlands, Thomson of France and the U.S. firms of Compression Labs Inc. and NBC.

They had fought intensely for the right to license HDTV and earn multibillion-dollar royalties from the technology. Surprisingly, however, it was differences over technical design, not money, that kept the groups at the negotiating table until shortly before Monday’s press conference.

“The negotiations were arduous,” said Robert K. Graves, an AT&T; vice president who participated in the talks. “I just hope we work together better as partners than we did at the negotiating table.”