The District is a more racially mixed city than a decade ago, gaining thousands of Hispanics, Asians and whites even as it continued to lose black residents, according to census figures released yesterday.

The figures, the first from the 1990 Census to provide racial and ethnic breakdowns of the city, show that the District remains predominantly black, but less so than 10 years ago: two-thirds of the population is black, compared with 70 percent in 1980.

But the city's white population rose for the first time since the 1940s, and now accounts for nearly 30 percent of the total, up from nearly 27 percent. Demographers said that most of the white increase was due to the 85 percent jump in the number of Hispanics, the city's fastest-growing ethnic group.

Hispanics, who are considered an ethnic group and not a race, can list themselves on census forms as members of any race, and they are counted a second time in a separate Hispanic category. The census said 5.4 percent of the city's residents listed themselves in that category in 1990, up from 2.8 percent in 1980.

In addition, the District is now 1.8 percent Asian or Pacific Islander, up from 1 percent in 1980, and 0.2 percent American Indian, unchanged as a proportion of the population. The "other race" category accounted for 2.5 percent of the population, up from 1.6 percent a decade ago, and demographers said that also included large numbers of Hispanics.

Despite the large jumps in the number of Hispanics, Asians and others, the overall population sank nearly 5 percent, to 606,900, because of an exodus of 49,000 blacks. Even so, the rate of total population decline slowed from previous decades, and the rate of black decline slowed from 16.5 percent in the 1970s to 11 percent in the 1980s.

"The District is becoming more cosmopolitan," said George Grier, a demographer with the Greater Washington Research Center. "Overall, the city is showing it still renews itself . . . . The District is retaining that mixed racial composition."

Release of the numbers sets the stage for the once-a-decade redrawing of boundary lines of the city's eight political wards, based on the principle that each must have approximately the same number of voters. Overall census figures also help determine the amount of federal aid to the city and are used by businesses in making decisions on location and marketing.

Ward-by-ward breakdowns, prepared by city officials, are not expected to be available for about 10 days.

The Census Bureau released its racial and ethnic figures for Virginia last month, and they showed a similar large increase in the population of Asians and Hispanics and also indicated that white flight from the inner suburbs had ended. Figures for Maryland are expected within a month.

Demographers credit the 11 percent drop in the District's black population to the continuing lure of suburban homes and schools. They dismissed the theory that the city's white population is growing because of gentrification by young whites of formerly shabby neighborhoods.

"A large proportion of that white gain could well be Hispanic," said David Word, a Census Bureau demographer.

District officials had predicted that a large increase in the number of Hispanics would show up in the 1990 Census, based on growing school enrollment and birth figures from local hospitals.

They criticized the Census Bureau for what they described as a lackadaisical effort to reach Hispanics, including illegal immigrants, mainly from El Salvador, who try to avoid government officials.

"It's still only a glimpse of what the real figure is likely to be," said Rita Soler Ossolinski, acting director of the city's Office of Latino Affairs. "I'm sure there are well over 60,000 Latinos in the District."