The United States plans to offer Germany the possibility of a unique "open skies" policy between the two countries, administration officials said yesterday.

Under the open skies concept, the airlines in either country would be permitted to fly to any point in the other. The proposal to be made during negotiations next month on a new bilateral air services agreement - was revealed by Richard N. Cooper, under secretary of state for economic affairs and Transportation Secretary Brock Adams.

They were the opening witnesses at a Senate Commerce Committee hearing on U.S. international aviation policy and on negotiation procedures.

In return for allowing Lufthansa German Airlines to fly directly to any U.S. city - it now has the authority to serve only five cities - the U.S. will ask Germany to agree to provisions the administration believes would meet major U.S. international aviation policy objectives. These include improving U.S. carriers' ability to compete in Europe, encouraging low fares, and providing better service to more cities.

Cooper and James R. Atwood, deputy assistant secretary of state for transportation affairs, said the major elements of the proposal, to be presented to German negotiators in Bonn on Sept. 12, include:

Eliminating current restrictions on the ability of U.S. airlines to pick up passengers in German cities and fly on to other European cities.

Removing the current power of the German government to limit the number of seats U.S. airlines can offer between Germany and other European cities.

Giving the United States the right to designate any number of its airlines to operate between the U.S. and Germany.

Allowing fare proposals of U.S., German and third-country airlines to go into effect unless both the U.S. and German governments disapproved them. (This would go a step further than the recent U.S.-Israel agreement that does not allow third-country airlines to be price leaders.)

Allowing both U.S. and German carriers to match any fares between German and other European cities.

Letting U.S. carriers use any kind of airplane on routes between German and other European cities, so long as the planes going out from Germany don't exceed the capacity of the planes they used coming in. This would avoid the kind of trouble Pan Americn World Airways ran into recently when it wanted to fly a smaller Boeing 727 from London to Paris instead of the large Boeing 747 it used from the U.S.

Eliminating restrictions on charter travel by allowing charters to operate according to the charter rules of the country in which they originate and not requiring them to meet the rules of the host country. The U.S. will also ask that U.S. carriers be given guaranteed access to the German charter market through a provision which bars the imposition of charter rules more restrictive than those agreed on by the two nations.

Cooper called the negotiations with Germany "extremely important" and said its acceptance of the proposed package "would be important in the annals of international aviation."

Hans Thilo, German Embassy first secretary in the transportation and communications section, said yesterday it was "difficult to say" what the reaction of Germany will be. "Our people in Bonn don't know yet the details of the proposal," he said. He noted that Germany has expressed interest before in gaining access to more U.S. cities, particularly in the South.

Yesterday's was the first of three days of hearings on legislation proposed by Chairman Howard W. Cannon (D-Nev.) and Sen. James B. Parson (R-Kan.) to establish a permanent, competitively-oriented international aviation policy and to institutionalize a unified, cooperative organization responsible for inplementing that policy.

"I believe that this administration has gotten its act together and is making the present organization work," Cannon said yesterday, but he said the history of U.S. aviation has a "poor record" on balance over the years.

"I have personally witnessed the growth of a cartelized, closed international aviation system and a disorganized and, at times, quarreling policy group among the agencies which share responsibility for developing and implementing our international aviation policy," he said!