A proposal by State Department security officials to follow the example set at the U.S. Embassy in Moscow and replace foreign workers with Americans at six other embassies in East European countries has been put on hold after complaints that the plan would impair the conduct of U.S. diplomacy in the region.

U.S. officials said that at a meeting here last week of American ambassadors in Eastern Europe, the department's new bureau of diplomatic security proposed that all foreign-national employes be replaced at U.S. embassies and consulates in the countries belonging to the Soviet-led Warsaw Pact: Poland, East Germany, Hungary, Czechoslovakia, Romania and Bulgaria.

But the ambassadors, backed by the bureau of European affairs, protested that the plan would not necessarily improve the security of their missions against espionage, the officials said. The ambassadors also argued that such a step would complicate embassy operations because the efforts of many mission staff members would have to be redirected from diplomatic work to performing routine chores now handled by the foreign workers.

As a result, the officials said, the proposal was put aside temporarily while further studies are made about the effects of reducing or eliminating the foreign employes. The officials said the studies would cover several possibilities, ranging from the complete elimination of foreign workers to partial cutbacks.

The question of what to do with foreign employes in communist countries came to a head last October after the Soviet Union, retaliated against U.S.-ordered cutbacks of Soviet diplomatic personnel at the United Nations. The Soviet Union then withdrew nearly 200 Soviet citizens who worked as clerks, drivers and mechanics at the American Embassy in Moscow and the consulate in Leningrad.

The situation was complicated further by allegations that some Soviet women employes had sexually compromised some of the Marine guards at the embassy and had gained their cooperation in breaching the embassy's security. As a result, the State Department has been under heavy pressure from Congress and counterintelligence agencies to introduce greatly enhanced security measures at U.S. diplomatic posts behind the Iron Curtain.

The officials said the European affairs bureau believes that firing the foreign workers is unnecessary and potentially counterproductive because the employes already are barred from sensitive areas of the embassies. The security breach in Moscow, they noted, occurred because of apparent laxity in controlling the Marine guards rather than a lack of control over foreign workers.

"The argument is between those security people who want all foreign workers replaced, period, and those who say that for most nonsensitive functions, such as doing routine clerical chores or running libraries, the foreign workers are most effective in terms of cost and efficiency," said one senior official who declined to be identified.

The State Department could not provide the number of foreign workers at the outposts in the Warsaw Pact countries.

To replace the Soviet workers in Moscow and Leningrad, the department contracted with a private, California-based firm -- Pacific Architects and Engineers -- to recruit 65 to 80 American replacements. At present, the officials said, 36 Americans have gone to work in Moscow under this arrangement, with more slated to be sent there in the coming months.

But, as one official put it, "While our experience since last fall shows it is doable working with Americans, it still is a much more cost- ly and less efficient operation

than when we had Russian work- ers."

The new U.S. ambassador in Moscow, Jack F. Matlock Jr., had been an outspoken proponent of replacing Soviet workers with Americans. However, the dominant view among department officials familiar with Eastern Europe is that the closed nature of communist societies makes it exceedingly difficult for foreigners to work in them effectively.

Indeed, many diplomats contend, since the jobs involved are rigorous and unrewarding, the types of American workers who could be recruited to take them would tend to be especially vulnerable to sexual or monetary compromise by communist agents.