The minority population of Northern Virginia grew at a faster pace than the white population over the past decade, and an influx of immigrants has left blacks outnumbered by Asians in Fairfax County and by Hispanics in Arlington, according to Census Bureau figures released yesterday.

The figures, the first from the 1990 Census to provide racial and ethnic breakdowns of the area's population, show that the number of white people in the inner suburbs has stopped declining for the first time since the 1970s. But three jurisdictions -- Fairfax City, Falls Church and Manassas Park -- did lose some white population.

The new information underscores that Northern Virginia gained more people than at any time in its history. The area's boom accounted for a third of Virginia's population increase in the 1980s, and it will translate into expanded representation in the General Assembly. The legislature will use the new numbers to redraw its districts and those of the state's congressional delegation this year.

Northern Virginia still is mainly white, but less so than it used to be: 80.8 percent white in 1990, compared with 86.7 percent in 1980, according to calculations by Ken Billingsley, a demographer with the Northern Virginia Planning District Commission, based on the new census numbers.

The area's proportion of blacks grew from 8.3 percent in 1980 to 9.6 percent in 1990. Other ethnic groups grew even more dramatically: Asians and "other" ethnic groups (including American Indians), jumped from 5.1 percent to 9.5 percent, and the share of people of Hispanic origin surged to 6.9 percent from 1980's 3.4 percent, he said. Billingsley's calculations covered nine jurisdictions: Arlington, Alexandria, Fairfax County, Fairfax City, Falls Church, Loudoun, Prince William, Manassas and Manassas Park.

Statewide, minority population growth was far less dramatic than in Northern Virginia. Alexandria and Arlington lost population in the 1970s and gained in the 1980s, with more than three-quarters of the increase accounted for by new Hispanic residents.

The most dramatic surge of minorities was in the area's outer ring of suburbs, which were among the state's fastest-growing in the 1980s.

Experts say those areas drew blacks, Asians and Hispanics for the same reason they appealed to whites.

"I would guess {it's} because of the availability and affordability of housing," Billingsley said. In addition, he said, "since the 1970s, there's been a substantial suburbanization of employment. There are more job opportunities in the outer suburbs."

The growing ethnic population is bringing Asian shopping centers to Baileys Crossroads, Hispanic community centers to Arlington and new wings to school buildings. It also is producing pressure on local governments to provide English classes, a broader ethnic mix in school history lessons and special programs for minority students.

Because many new migrants have higher-than-average birth rates, "this has a lot of implications for the schools," said George Grier, a demographer with the Greater Washington Research Center. "The schools have to deal with larger populations than expected."

The latest census information does not say where the new minority residents came from, but local demographers say many Asians and Hispanics moved from other countries, drawn by relatives or friends who found jobs here. Historically, most blacks in Virginia's suburbs came from other Southern states.

Release of the numbers officially opens Virginia's once-a-decade task of drawing new boundaries for every voting district, based on the principle that each must have the same number of voters. Figures for Maryland and the District are expected in several weeks. Census numbers also are used by the federal government to allocate billions of dollars in grants and by businesses to plan marketing and where they locate.

The General Assembly meets in April to redraw its 40 Senate and 100 House districts, so elections in the new districts can be held this fall. Virginia's 15.7 percent population increase since 1980 will bring it an 11th congressional district, to be drawn in time for the 1992 elections.

Northern Virginia's growth boom is expected to bring the area more political clout in the General Assembly, adding three more delegates to the area's current 21 and the equivalent of 1 1/2 senators to the region's eight. In all, Northern Virginia will have a quarter of the seats in the General Assembly, and Republicans hope the suburban growth will bring them new strength in the Democratic-dominated body.

The last attempt at legislative redistricting was so contentious that it inspired several revisions and protracted court fights.

Civil rights and civil liberties groups have announced plans to fight to make the state's new congressional seat a mostly black district in Tidewater, saying that such a district is called for by the federal Voting Rights Act if it can be done reasonably.

But Northern Virginia Democrats are pushing for the new seat in the Washington suburbs, arguing that is where the growth has occurred.

Republicans favor a black district, reasoning that black voters are not GOP supporters and such a district would strengthen Republican holdings elsewhere.

Virginia's redistricting plan must be approved by the U.S. Justice Department, and both sides say a lawsuit is likely.

Congressional redistricting is not expected until the fall, because legislators must deal with their own districts first.

Staff writer Barbara Vobejda and staff researchers Bridget Roeber and Shaun Hill contributed to this report.