Virginia's legislative auditors have urged the University of Virginia and Virginia Polytechnic Institute and State University to reduce costs by seeking less expensive offices and other facilities for their Northern Virginia operations.

The Joint Legislative Audit and Review Commission questioned a recent decision by the two institutions to lease offices, classrooms and other space for $485,000 a year in an office building near the Capital Beltway and Rte. 50 in Fairfax County.

"The current space leased by the two universities is not only expensive, it is also the least efficiently used," the commission said in a new report. It urged the two institutions to consider sharing facilities with George Mason University and Northern Virginia Community College, using more public school classrooms and purchasing an abandoned school building.

Officials at the two universities disputed the auditors' conclusions. "We did all of that before," said William F. Lanier, director of U-Va.'s Northern Virginia center. He said officials had studied the options proposed by the auditors before leasing their new quarters, but had not found sufficient space at a suitable location.

John C. Smart, an assistant dean at Tech, described the cost of the current lease as "very reasonable" and said the rented space is "not underutilized."

The auditors' recommendations were outlined in a study of possible moves to consolidate offices used by state agencies in Northern Virginia. The universities were the only institutions urged to seek new quarters.