A federal judge has ruled that the FBI misused a grand jury subpoena to retaliate against a Hispanic FBI agent who brought a landmark class-action discrimination suit against the agency.

U.S. District Judge Lucius Bunton, in a 17-page opinion issued Friday, said the FBI obtained the grand jury subpoena to get telephone records, an effort to determine if Special Agent Bernardo Matias Perez made phone calls to his superiors as ordered on a trip to Leesburg, Va., in 1988.Bunton said the securing of the grand jury subpoena "was not legitimate" and that the reason given by the FBI for the subpoena "was but a pretext for the purpose of retaliating against Perez" for filing anti-discrimination complaints against the FBI.

"At no time was permission of a U.S. district judge to utilize the telephone records for purposes other than a criminal investigation sought by any person connected with the investigation of Perez," Bunton wrote.

"The telephone records secured under the subpoena were used by the FBI in the course of an administrative investigation of Perez without the knowledge of the U.S. attorney, who issued the subpoena on behalf of the grand jury or the grand jury itself," he said.

Bunton ruled in favor of Perez and 310 other Hispanic FBI agents on Sept. 30. The Hispanic agents contended they have been victims of discrimination by the FBI. Bunton ruled the FBI was unfair in its promotional, transfer and training policies relating to Hispanics.

The judge said the subpoena seeking telephone records was discovered in an administrative investigation file by U.S. Magistrate Janet Reusch in El Paso in April 1988, while the Hispanic agents were trying to find out information for their lawsuit. Perez did not know he was the subject of a grand jury subpoena, lawyers said.

Bunton said the FBI "did not articulate a legitimate non-retaliatory reason for securing the grand jury subpoena."

The charge of retaliation came up during the nine-day trial in El Paso in August and was heard by Bunton in Midland Nov. 15.

Testimony in the trial indicated Hispanic agents have been assigned to tedious Spanish-language wiretaps, are transferred to offices on the "taco circuit" where there is no chance for advancement, and often are assigned to the most dangerous jobs in the bureau.

Administrative action to get Perez fired was initiated several weeks after the 311 Hispanic agents filed the class-action discrimination suit in January, 1987, court records show.

The FBI said Perez perjured himself in testimony against former Special Agent Richard Miller in 1985 and 1986. Miller, a friend of Richard Bretzing, special agent-in-charge of the Los Angeles office, was convicted of spying and sentenced to two life terms, plus 50 years.

Perez testified during the class-action trial that Bretzing, a bishop in the Mormon church, used his authority to protect Miller, a fellow Mormon, despite Perez's recommendation that he be dismissed as a security risk.