The Department of the Army has agreed to seek approval from a judge in the United States before it begins wiretapping any American citizen living overseas.

The Army's decision to amend its regulations on electronic surveillance is believed to mark the first time that a government agency has officially extended to Americans abroad the same protections against illegal searches guaranteed to citizens in the United States.

The requirement that the Army obtain a warrant from a U.S. court before placing a wiretap would not apply in cases in which there is information that a person either is an agent of a foreign power or when they are in possession of foreign intelligence material.

If an emergency situation demands immediate action, the Army, under the new policy, will apply for a warrant within 72 hours after a wiretap begins.

The warrant requirement was the key element in the settlement yesterday of a massive, six-year-old lawsuit brought by American citizens, living in Germany in the early 1970s, who contended that they were subjected to illegal wiretaps and infiltration.

The settlemtnt agreement was approved yesterday by U.S. District Judge Louis F. Oberdorfer.

One organization involved in the lawsuit, the Berlin Democratic Club, was at the time an official branch of the Democratic Party and had actively supported the presidential candidacy of Sen. George McGovern (D-S.D.). Citizens who brought the lawsuit also had opposed U.S. policies during the Vietnam War era.

As part of the settlement agreement, the Army said it would pay a total of $147,000 in costs which will be divided up among 21 individuals and the Lawyers Military Defense Committee, which joined in the lawsuit. The American Civil Liberties Union, which brought the case to the federal court here in 1974, will receive $3,000 from the Army.

ACLU lawyer Mark Lynch said yesterday that the wiretap agreement was "the first time any component of the government has conceded to the warrant requirement overseas."

Lynch described the warrant requirement as an "enormous step forward" from the current state of the law on illegal searches as it applies to U.S. citizens living overseas.

The settlement stated that the Army would amend its regulations on electronic surveillance activities to include the warrant requirement within 180 days. In settling the case, neither the government nor the Army admitted any wrongdoing in connection with the citizens' allegations.

Assistant U.S. Attorney Royce C. Lamberth yesterday described the settlement as a "reasonable accommodation" that ended a protracted lawsuit that became increasingly expensive to the government as it made its way through the court.

"This case arose during the Vietnam War era when times were particularly tense, especially in Europe. Times have changed now, and the rules have changed," said Lamberth who represented the Army throughout the litigation.

The settlement agreement on the warrant requirement parallels a 1976 decision by the late William B. Jones, then chief judge of the federal court here, who ruled that the Army needed judicial approval for wiretaps.

The Army also has agreed to observe a complicated formula for disclosure of documents and information it may have collected through wiretaps on any of the organizations or citizens who brought the lawsuit.