A top Civil Aeronautics Board official has warned that the United States may be forced to withdraw recently granted routes to foreign airlines or even denounce the procompetitive air agreements that spawned them if other nations do not live up to the provisions of the pacts.

Although Michael E. Levine, CAB general director of international and domestic aviation, declined to name any countries, other sources said Levine's remarks were directed to troubles U.S. airlines have been having with West Germany and South Korea.

"Preserving our international aviation system requires that the United States take the steps necessary to assure that our bilaterals do not become a one-way street," Levine told the International Aviation Club here on Tuesday.

In signing several important aviation agreements over the last two years, the Carter administration has sought to increase competition in international aviation. To do so, it has given other nations the authority to fly to more U.S. cities in exchange for the right to name unlimited numbers of U.S. airlines as it wants to fly to the other countries, and for increased freedom for U.S. airlines to set their own fares and schedules.

Sources said that U.S. airlines seeking to take advantage of liberal provisions of agreements signed with both West Germany and South Korea have encountered unexpected difficulties. Ground handling has proved difficult to arrange in South Korea for U.S. airline services, for instance, one source said, while the West German government failed to administer with the promised "light touch" a bilateral pricing provision giving the Germans the right to turn down U.S. airlines' proposals for air fares on trips originating in Germany.

"If we exchange route rights for market access, and the other country then refuses to give our carriers the market to which they are entitled, we must be willing to take action against the route rights which were the quid pro quo for the market access," Levine said in his speech.

"In extreme circumstances, the United States should even be willing to consider denouncing an agreement," he added. "This is certainly not the preferred course, but it may be made necessary by the other country's refusal to live up to the agreement it has made."

On domestic aviation, Levine said the CAB is committed to finding the least anticompetitive solutions to problems of airport facilities access and fuel supplies following expected increases in competition under the Airline Deregulation Act.

Levine also disclosed a new study which concludes that the most efficient and least anticompetitive way to distribute airport slots to airlines is to hold a sealed-bid, one-price auction. The study was produced by a consultant hired jointly by the CAB and the Federal Aviation Administration.