BIG CITIES SUFFER COURT SETBACK\L.A. to lose $150 million in census case; Southland won't gain\House seat.

Byline: Rick Orlov Daily News Staff Writer

The U.S. Supreme Court dealt a blow Wednesday to Los Angeles and other major cities by rejecting a call to revise the 1990 census upward to compensate for an undercount of minorities.

In a unanimous decision that will cost the city of Los Angeles more than $150 million and California a representative in Congress, the court said the Census Bureau made an extraordinary effort to adjust the population count and that no remedy is necessary.

"In 1990, the Census Bureau . . . was successful in counting 98.4 percent of the population," wrote Chief Justice William Rehnquist.

The court said it has been known for more than 50 years that some segments of the population - particularly minorities - are undercounted, but that the bureau is improving its methods.

Los Angeles officials, calling themselves disappointed by the court's ruling, said they hope the census in 2000 will deal with issues raised in the lawsuit, originally filed by New York City.

"We respect the court's decision," Mayor Richard Riordan said in a statement. "Nonetheless, minorities in Los Angeles and in other cities historically have been undercounted.

"We believe that more than 100,000 Angelenos were not counted by the federal government in the 1990 census. This must change. Every Angeleno deserves to be counted."

Riordan said the decision will mean the loss of $150 million in federal funds - primarily community development block grants - allocated on a population basis.

"In the time of fiscal belt-tightening, these losses hurt all the more."

The ruling also costs Southern California - probably in the Orange-Riverside County area - an additional member of Congress. California already has the largest congressional delegation with 52 members in the House of Representatives.

A lower court ruled that the Census Bureau would have to adjust its 1990 figures, but the Clinton administration appealed despite pressure from local officials in Los Angeles and New York.