The U.S. Court of Appeals here yesterday ordered the Justice Department and a House subcommittee to take a compromise approach to their year-long dispute over the panel's access to documents concerning the FBI's foreign security surveillances.

In gingerly sidestepping an outright order in behalf of either side, the three-judge panel unanimously said the compromise it proposed should be tested thoroughly before further litigation over the issue.

The ruling allows the House subcommittee, chaired by U.S. Rep. John E. Moss (D-Calif.), to have access to 10 uncensored documents concerning foreign security surveillances approved by the Justice Department in the years 1972 and 1975. In addition, the panel can have access to censored documents concerning all other such surveillances in those years.

Subcommittee investigators cannot take their notes concerning their study of the uncensored documents away from FBI offices here, however, and must report orally to panel members on the contents of those documents, the court said.

The taking of notes has become an issue because the panel said the staff notes were needed for its work on Capitol Hill. The Justice Department opposed note taking because, under House rules, any member of Congress would then have access to the material.

Under the court order, a District Court judge would settle further differences over the material in closed proceedings.

Except for the issue of notetaking, the court-ordered compromise is quite similar to the most recent Justice Department suggestion as to how the controversy could be temporarily resolved.

The issue over congressional access to foreign security surveillance information arose when the Moss subcommittee subpoenaed certain documents from AT&T concerning its practice of leasing telephone lines for such FBI wiretaps. The House panel said it is seeking to determine whether the use of those secret surveillances under the "national security" powers of the executive branch has been abused.

The Justice Department got a court order stopping AT&T from turning over the materials to Congress, on the grounds of national security.

The subcommittee appealed that ruling, but several months ago the same appellate court panel refused to rule even on threshhold legal questions and suggested instead that justice and the panel negotiate further.

Those negotiations failed, however, and the case then returned to the appellate court for yesterday's ruling.

In an opinion written for the court yestereday, U.S. Circuit Judge Harold Leventhal resolved that the issue of congressional access to the material was properly before the court, but added that the court still wanted to pursue an approach of "gradualism" before deciding in favor of either side in a case involving the separation of posers between Congress and the Executive Branch.