A dispute has erupted within the West German government over support for the Reagan administration's policy toward Central America, reflecting growing worries in Europe that the volatile regional conflict could strain alliance unity as debate heats up over deployment of new nuclear missiles.

Helmut Schaefer, a leading foreign affairs spokesman of the ruling coalition's junior partner, the Free Democrats, today criticized the Reagan administration for exacerbating East-West tensions with its planned military maneuvers in Central America. He urged that Bonn not support U.S. policy "out of mistaken understanding of solidarity."

Schaefer, who just completed a tour of Central America, said Chancellor Helmut Kohl's Christian Democratic Union has failed to develop its own views on the region and he attacked conservatives within the coalition for consenting to stop economic aid to Nicaragua. The government is currently weighing a proposal to end economic aid to Nicaragua while reinstating aid to the U.S.-backed government of El Salvador that was suspended earlier this year.

The opposition Social Democratic Party has called for a major debate on Central America when parliament reconvenes in September and there are mounting signs that unfavorable public opinion in Europe about the U.S. role in Central America could have an impact on the controversial deployment of new nuclear missiles.

Recent demonstrations against the nuclear missiles have included signs and slogans critical of U.S. policy in Central America. European governments have begun to fear that the scheduled U.S. maneuvers will give added impetus to the general anti-American tone of the protests.

If the military maneuvers scheduled for U.S. forces in Honduras make President Reagan appear bellicose, then the missile deployments "will not be seen as a defensive move but rather a dangerous one," as a French political leader put it.

France and the Netherlands have taken the lead in asserting support for the four-nation Contadora group--Colombia, Panama, Mexico and Venezuela--in the search for peaceful compromise that would minimize outside interference in Central America.

French Foreign Minister Claude Cheysson, who traveled through Latin America last week, announced that France, which in the past has sold helicopters and other military equipment to the Sandinista government in Nicaragua, would no longer do so in deference to the wishes of the Contadora group.

Cheysson also criticized U.S. maneuvers saying, "This isn't a step forward in the search for peace,"

At the European Community's summit in Stuttgart, in June, the 10 heads of government issued a declaration supporting the Contadora group and said the Central American conflict could not be solved by military means but only by "a political solution springing from the region itself."

According to sources in Athens, the Reagan administration later sent a letter to the community's political cooperation group decrying the criticism of U.S. policy implicit in the declaration, which underscored support for "principles of noninterference and inviolability of frontiers." Greece is currently head of the political cooperation group.

Following the U.S. protest, Britain sought to disavow the relatively strong language, saying the statement received only scant scrutiny by the heads of government.

British Prime Minister Margaret Thatcher, who was locked in a marathon struggle at the summit to secure a $650 million budget rebate for her country, also did not wish to offend the sponsor of the declaration, the Netherlands.

The Dutch government pushed the initiative largely in response to growing public resentment in the Netherlands toward U.S. backing for military governments in Central America. The resentment has increased since four Dutch journalists were killed in El Salvador last year.

In Bonn, the Kohl government has sought to minimize differences with the U.S. approach to Central America because it did not wish to aggravate tensions with Washington before deployment of new Pershing II missiles. While backing the community's initiative and the Contadora group, Kohl shares Thatcher's belief that Europe must not interfere with the United States where its vital security interests are perceived to be at stake.