If approved by several regulatory agencies and Congress, the deal will give Lockheed Martin (LMT), one of the world's largest aerospace companies, a running start in the increasing competition to move data, video and voice through satellites, which are highly competitive in areas that are not yet saturated by fiber cable.

``The beauty of today's announcement is that it gives us instant capability because of the credibility that Comsat brings to the merger,'', chief executive officer John Sponyoe of a Lockheed Martin subsidiary, Lockheed Martin Global Telecommunications, said in a telephone interview.

The new Lockheed Martin subsidiary -- which began in April -- is aimed at increasing the company's share of the global network services market serving corporations and other large entities.

In the first phase of thetransaction, with an estimated value of $1.3 billion, Lockheed will begin a cash tender offer to purchase up to 49 per cent of the outstanding common stock of Comsat (CQ) at $45.50 per share, a roughly one-third premium over the market value of Comsat, on which closed Friday at $34.125.

Lockheed shares closed down $3.50, at $100, on the New York Stock Exchange on Friday.

Comsat has about 52.4 million shares outstanding.

The first phase will require approval by Comsat shareholders, the Federal Communications Commission and the nation's antitrust agencies.

The companies say they can win that regulatory approval in six to nine months.

In the second phase, Lockheed Martin, which also is based in Bethesda, will exchange its common stock for Comsat common stock at a ratio of 0.5, with an estimated value $1.4 billion, based on Lockheed's recent market prices -- with the same one-third premium on shares.

But to complete the second phase, Congress will have to act. Comsat was established by Congress in1962 as the country's representative for the international Intelsat system, which provided satellite communications around the world.

Since then, competition from other satellite systems and fiber carriers has emerged.

Congress has been moving to cut the remaining strings with Comsat and send it out on its own.

In May, the House of Representatives overwhelmingly passed a bill by commerce committee chairman Thomas Bliley to privatise Comsat, on a 403-16 vote.

``The days of high flying satellite monopoly are numbered,'' said Bliley, a Virginia republican, when the bill passed.

The bill would eliminate the cap on ownership that prevents Lockheed Martin from acquiring more than 49 per cent of the company.

But Comsat has opposed the wide-ranging bill because it also would permit competitors and customers to directly access the Intelsat system without going through Comsat, as they do now.

So what will Comsat and Lockheed do?

``We'll all be working with Bliley,'' said Sponyoe. At the sametime, Comsat continues to insist that companies in the United States should obtain Intelsat services through it.

Lockheed and Comsat expressed optimism that a bill could clear Congress as soon as this session and that the second phase would be Lockheed completed in 1999.