It's a little-known fact that most Americans stationed in U.S. embassies around the world work for government agencies other than the State Department--a sore point with diplomats who feel outnumbered in their own bailiwick. The Justice Department has its legal attaches, the Interior Department its mineral attaches and the Agriculture Department its foreign agriculture experts. Even the Library of Congress maintains outposts in selected embassies.

Now the Commerce Department's International Trade Administration has gained its own foreign service, and is busy replacing State Department commercial attaches with its own recruits.

Not only that, the ITA has merged its Foreign Commercial Service outposts in 67 countries with its domestic offices in 48 American cities--bringing together in one organization the people who encourage U.S. companies to sell overseas and those who deal with potential purchasers of American-made products.

Acording to Deputy Assistant Secretary Kenn S. George, the orientation of these attaches is different from the State Department officers they began replacing in April, 1980, when Congress transferred the commercial attache jobs to the new Foreign Commercial Service.

Instead of diplomats, George is hiring private businessmen. And there's a new emphasis on language skills so that the commercial attaches can deal directly with local businessmen in their own language.

Until recently, for instance, only one of the six commercial attaches in Tokyo spoke Japanese. "By the time we get through with our current deployment," said George, "five out of six attaches in Tokyo will speak Japanese." The chief commercial attache, moreover, will be headed by a former official of the Bank of America, William Rapp.

In Bonn, Kenneth D. Blum, former president of the American Chamber of Commerce of Germany and a retired corporate executive, has taken over as commercial attache. The new commercial attache in Brussels is Hank Schmidt, the former international sales director of the Skil Corp. who speaks five languages. Melvin W. Searls Jr., a former Exxon executive and vice president of the U.S. Council on U.S.-China Trade, has taken over as commercial attache in Peking.

Under what amounted to a treaty between the State and Commerce Departments, ITA was given three years--until April, 1983--to phase in its own officers in posts overseas.

About 40 foreign service officers shifted from State to Commerce to form the nucleus of the foreign commercial service. These including Calvin C. Berlin, who held the high rank of minister-counselor at State and now serves as commercial attache in Mexico City.

"We're taking the best people from any source. Our first choice is to build our own service. But we will take people on detail from the State Department," said George.

So George G. B. Griffin, the former No. 2 man in the U.S. Embassy in Kabul, Afghanistan, has been detailed to Commerce as the attache in Lagos, Nigeria, and Hallock R. Lucius--the subject of a turf battle between State and Commerce--remains as commercial attache in New Delhi. George said the battle was settled after Ambassador Harry Barnes expressed his strong desire to have Lucius stay on, despite Commerce view that the job should go to one of its own officers.

George said the main goal of all the changes is to improve Commerce's ability to bring American sellers and foreign buyers together to improve the United States' trade position in the world.

"We're trying to create a service organization," he said.

To that end, the ITA is trying to clear out the bottleneck in Washington by allowing foreign posts to deal directly with domestic offices about potential overseas sales.

Moreover, George said Commerce is realigning its staff, moving slots from western Europe to South America, Africa and Southeast Asia, where there are a growing number of potential markets and fewer alternate sources of information about American business.