Some of the Pentagon's largest contractors, including Boeing Co. and Lockheed Martin Corp., will begin a joint effort today to encourage development of technology standards that will ensure weapons systems of the future can communicate with each other.

In the past, systems built by different manufacturers used incompatible technologies that made it difficult for satellites, fighter jets and ships to communicate and share data, industry officials said. The Pentagon's push toward using computer networks on the battlefield has made the interoperability of future and current systems more important, they said.

This is about the "government being able to be confident that if they buy a system from Northrop Grumman that it will work with a Boeing system," said Alan Murdoch, director of network-centric operations at Northrop Grumman Corp. "We need to be able to talk, exchange data, communicate, from one war fighter to the next."

The contractors have formed the Network Centric Operations Industry Consortium, of which Murdoch is chairman. It was initially pushed by Chicago-based Boeing and now includes 30 companies such as Northrop Grumman, BAE Systems PLC and Raytheon Co. The group will be self-funded.

The group will identify common operating standards and emerging technology trends. It will agree that technology developed in accordance with the consortium's recommended standards will be made available to all members, industry officials said.

"If you bring a proprietary product into the network, then it becomes public," said Carl G. O'Berry, Boeing's vice president for strategic architecture and one of the original proponents of the group. The Pentagon has repeatedly attempted to establish industry standards for interoperability during the past 20 years, but by the time the rules have been established the technology has evolved, said O'Berry, a retired Air Force lieutenant general who worked on these issues at the Pentagon.

The effort initially met resistance from one of its largest members, Bethesda-based Lockheed. The company was concerned the group would adopt an architecture based on Boeing proprietary technology and was being established without government input, said Judy Gan, a Lockheed spokeswoman. "We had some concerns about their position at the time," Gan said. But "Boeing has abandoned that approach. . . . Our concerns have been addressed."