A rezoning proposal to build an international university in Loudoun County, scheduled for action today, is one of the few bright spots in a county facing a serious real estate and tax crisis.

The bilingual university, intended to improve Japanese-American business and cultural relations, would occupy 545 acres previously designated for new houses at Lansdowne, a much-delayed 2,267-acre planned community. If approved, the university would solve a lot of problems.

The institution's Japanese backers would have a prime location to advance their mission. Lansdowne's owners would be able to scale back their troubled development. Loudoun officials and taxpayers would gain a small measure of fiscal relief.

The county staff has urged the Loudoun Board of Supervisors to approve the rezoning application, clearing the way for Washington International University in Virginia to open in 1992 or 1993 on Route 7 east of Leesburg, a few miles from Dulles International Airport. Approval would free county government from building and staffing public schools and other services for potential house buyers at the site, generating tax dollars instead. According to the Xerox Realty Corp., which owns Lansdowne, the university would contribute nearly $4 million in taxes during 20 years, and its annual payroll could reach $36 million.

Deputy County Administrator James R. Keene Jr. said the county has "worked very closely with Lansdowne and Washington International University to bring this unique idea to reality. We're extremely excited about the university coming to Loudoun County."

So far, no public opposition to the proposal has surfaced.

Assessments for commercial and industrial land are plummeting in Loudoun, after years of rapid increases attributed largely to speculation. Sales of new houses are low and county government tax revenue is drying up.

While Loudoun officials are looking for ways to scale back the county budget about 10 percent for fiscal 1992, they and state officials are putting a full-court press on United Airlines to locate a $700 million maintenance plant in the county. Competition for the economic development plum is fierce among several U.S. cities.

One of the few major businesses to announce in recent months that they will build in Loudoun also chose to be near a university site. E-Systems plans to open at the Charles E. Smith Co.'s University Center, a few miles east of the Xerox site, where George Washington University has begun offering graduate engineering courses.

The Japanese-backed Washington International University, officials said, also would lure business to Loudoun. "The evolution of any significant city in the world has been based on a university," said Cathleen Magennis, Xerox vice president.

The university's financial backers, who include former Japanese labor minister Toshio Yamaguchi, said they will have an opportunity to shape two nations' foreign policies and business practices well into the 21st century by teaching top Asian and American students how to understand each other better.

The sales price for the university land and the estimated cost of the school's construction have not been revealed. Officials say more than 1.3 million square feet of building space may be needed for a student body that eventually could reach 3,000 -- half Asian and half American.

State permission would be required for the school to enroll students, and a regional association would rule on accreditation. University Executive Director Katsuyuki Imamura said Washington International would be one of a few universities started from scratch in the United States in decades.

The university would become the third major development at Lansdowne, a multibillion-dollar project first approved in 1985. An $82 million conference resort is scheduled for formal opening next month, near the Xerox Training Center.