The United States' much-discussed "urban crisis" is fast losing its unique status in the world.

Britain's Parliament, upset by the spread of "grey" areas of inner-city housing decay and industrial flight in such older industrial cities as Birmingham, Liverpool and Glasgow, recently adopted an Inner Urban Areas Act with features strikingly similar to the Carter administration's urban policy.

West Germany, though its cities still appear basically healthy, reports mounting concern about loss of middle-class residents, a new-born minority problem (millions of south European "guest workers"), and how to maintain the attractiveness of historic old city centers as automobiles exact an ever-heavier environmental and social toll.

The Netherlands and Denmark, long models of compact and successful urbanization, report new worry about declining center-city population and incipient suburbanization. Norway reports "deterioration of the quality of urban life" and problems in city management. Spain is concerned about physical deterioration in its cities, Austria about city traffic pressures, Japan about how to prevent sprawl.

No less than 17 of 19 Western nations said innercity problems were either their No. 1 problem or close to it at a September meeting of the Parisbased International Organization for Economic Cooperation and Development (OECD).

Ideally, nations facing common city problems should be able to exchange experiences and transfer potential solutions across borders, thus saving each nation and city the painful necessity of reinventing the wheel as each turn in urban issues is reached. Past experience, however, shows such exchange is exceedingly difficult. Each country wears its own cultural blinders and suffers from some degree of parochialism -- unwillingness to accept innovations from elsewhere.

But in late November urban experts from three nations -- the United States, Great Britain and West Germany -- met here in Birmingham to inaugurate a rather promising "Trinational Cities Exchange." The project will aim at "accountable" transfer in which teams of local officials and urban experts agree in advance to do careful homework on another country's special urban conditions. They must pledge, after foreign inspection trips, to implement just as much of what they find reasonably transferable to their home situations. Happily, the project isn't officially government-sponsored, but rather the creation of the German Marshall Fund of the United States, a foundation set up with a gift from West Germany in gratitude for the postwar Marshall Plan. As the three national delegations left Birmingham, they talked of mounting international transfer teams on distinctly small-scale solutions to city problems -- as opposed to the "mega-solutions," so often disasters in practice, of past years.

The Americans plan to send transfer teams to Europe to investigate better tools and techniques to promote modest-sized economic enterprises in cities, including incubation of new firms. Anther selected U.S. concern is "livable cities" -- how most European cities retain a richness and quality of life, from preserving historic buildings to taming the automobile. U.S. teams will also examine how Germany's non-profit housing associates are so successful in building and then maintaining high-quality low- and medium-income housing.

British teams will visit America and Germany to learn more about economic development agencies in which private business plays a major role, about community development corporations, about community self-help in social services, and finally about techniques for renewing old housing under private auspices, such as the U.S. Neighborhood Housing Services program.

West Germany is especially concerned about the more than 4 million guest workers from Turkey and other south European nations, many deficient in basic German language and cultural skills, who are crowded into its cities. A German team will be sent to see how the English deal with their "New Commonwealth" urban residents (West Indian, Asian, etc.) and then cross the Atlantic to search out constructive hints in how American cities work with large Hispanic populations. The Germans also want to learn more about U.S. citizen participation, especially self-help measures in the subsidized housing field.

The idea in each instance is not to import a carbon copy of another nation's urban practice, but rather the seed of an idea that can flourish under the special cultural and economic conditions of the importing country.

Transfer teams will consist mostly of local officials. But there will be one exception, marking the most unexpected decision for the upcoming exchanges. The United States will send a particularly high-lever team -- congressmen, governors, possibly White House staffers -- to study why German cities seem so much more autonomous and fiscally stable than America's. One clue. German cities deal only with the state governments, never directly with the central government in Bonn. The Germans seem to have developed a model of tidier, more accountable federalism. Ironically, it's a model the United States imposed on West Germany after World Wat II -- but doesn't practice itself.