West German Chancellor Helmut Schmidt said today that the Reagan administration's latest move to frustrate the planned Soviet gas pipeline to Western Europe had endangered Europe's confidence toward America and U.S. credibility abroad.

The chancellor, in his most pointed criticism so far of the U.S. action, called the threat to alliance relations "very, very sad" in view of what he said had been Reagan's notable success "in creating confidence and credibility for himself" during the president's visit earlier this month to Western Europe.

Speaking informally to a high-level group of European and U.S. government and security affairs officials that included the U.S. assistant secretaries for both defense and state, the West German leader was more candid and sharp in showing his annoyance over Reagan's decision to extend the pipeline sanctions than he had been in an official address to the West German parliament yesterday or in earlier government statements he had authorized.

Schmidt underscored his pique at what he said was Reagan's failure to consult with West European leaders. He said there had been ample time during confidential discussions at Versailles for the president to have mentioned that he was considering further sanctions against the pipeline, but this was not done.

Schmidt's criticism of U.S. policy extended to what he suggested was disregard for or insufficient awareness of the impact U.S. decisions have on the more vulnerable West European economies.

He also strongly contended that the U.S. attack on the pipeline would have no effect in changing Soviet strategy toward Poland or much else, asserting that "next to China, the Soviet Union is the one country in the world least dependant on trade and economic exchanges with the West." Only about 1 percent of Soviet national production depends on trade with the West, Schmidt said.