Attorneys for Marine Lt. Col. Oliver L. North are appealing a federal judge's order that he comply with a grand jury subpoena obtained by the independent counsel investigating the Iran-contra affair.

North's lawyers yesterday filed a notice of appeal to an order issued July 10 by U.S. District Court Chief Judge Aubrey E. Robinson Jr. in connection with the investigation by Lawrence E. Walsh.

The notice of appeal was sealed because the case involves grand jury matters. More than 20 envelopes of sealed material also were transmitted to the U.S. Circuit Court of Appeals here, according to the docket sheet in the case.

Robinson last week rejected North's challenge to Walsh's authority to obtain the grand jury subpoena.

Court records indicated that North was held in contempt of court May 8 for refusing to comply with the subpoena, which sources say seeks a sample of his handwriting.

The contempt order was appealed to the circuit court, which ordered Robinson to consider North's challenge to Walsh's prosecutorial authority.

Robinson upheld Walsh's authority in his ruling last week. He also issued a sealed order, which presumably directs North to comply with the subpoena.