Federal prosecutors Wednesday unsealed an indictment charging seven people, including the brother of Contra leader Adolfo Calero, with illegally supplying mercenaries and weapons to the Nicaraguan rebels.

The long-awaited indictment did not mention any Reagan administration officials or Calero himself.Mario Calero was accused of recruiting and paying for mercenaries with the help of a Texas millionaire, Maco Stewart, and anti-Communist Cuban activists from the Miami area. Adolfo Calero's brother is based in New Orleans.

Also among those indicted were Thomas Posey, head of Alabama-based Civilian Materiel Assistance, and Jack Terrell, a former mercenary who later blew the whistle on the alleged illegal operation.

All seven are accused of violating the U.S. Neutrality Act, which bars hostile actions against foreign governments from U.S. soil.

"According to the indictment, defendants recruited soldiers in the United States to participate in military expeditions and enterprises against the government of Nicaragua," a statement from the U.S. Attorney's office said.

The indictment mentions two groups totaling 19 soldiers recruited in early 1985, with money provided from Stewart to Mario Calero. It gave no details on who the soldiers were.

In one case cited from 1985, Terrell is accused of ordering his soldiers to help Contra rebels destroy a bridge at Sinsin, Nicaragua.

The indictment refers to "others known and unknown to the grand jury" but does not list the conspirators.

Interim U.S. Attorney Dexter Lehtinen withdrew from the case because he had represented retired Maj. Gen. John Singlaub while in private practice.

Lehtinen emphasized that his former client, a leader in private efforts to raise aid for Contras, wasn't directly involved in the case.

The prosecutor Wednesday refused to answer questions about any possible involvement by administration officials in the alleged scheme.

Terrell and Joe Adams, a former bodyguard of Adolfo Calero, could face up to 33 years in prison on Neutrality Act violations and charges they transported firearms without a license.

Jose Coutin, an anti-Communist Cuban activist and gun store owner, faces 13 years on Neutrality Act violations and allowing someone to use his passport.

Posey, Calero and Stewart face up to eight years each in prison, according to the U.S. Attorney's office. Alex Martinez, an anti-Castro Miami Cuban and account executive, was also charged with violating the Neutrality Act.