Major Western industrialized countries welcomed President Carter's energy-saving plan yesterday seeing it as giving a potential boost to the world's economy by lessening the U.S. balance of payments deficit.

A West German government spokesman in Bonn said the program showed America's determination to fulfill its responsibility as the world's largest energy consumer and Bonn officials called the Carter plan "solid."

West Germany has pressed strongly for a decrease in U.S. oil consumption and the spokesman said Carter informed Chancellor Helmut Schmidt of his intention before making them public.

French President Valery Giscard d'Estaing sent a message to Carter promising French support for the plan, presidential spokeman Pierre Hunt said in Paris.

The Japanese government, in applauding Carter's move, said it, too, would decide later this month on measures to conserve energy during the summer and fall. Japan imports almost all of its oil.

Chief Cabinet Secretary Rokusuke Tanaka said Japan understood that Carter acted to restrain inflation. He said the Japanese government hopes the measures will help the United States improve its balance of payments and stabilize the dollar and thus be better for other developed countries.

Carter's announcements had little impace on the dollar during trading at the Tokyo foreign exchange today. One banker said traders responded with only mild enthusiasm because Carter plans to decontrol the price of domestic oil gradually over a 28-month period instead of doing it all at once.

In London, Prime Minster James Callaghan warmly welcomed the president's new energy measures, and sympathized with American citizens over the burden they will now have to shoulder. The president sent the British leader details of his plans before he made them public Thursday night.