The Supreme Court yesterday made it possible for the disputed 1980 census count to become official -- a major victory for the Census Bureau in its battle with state and municipal leaders who claim it has failed to accurately count their populations.

The court voted 7 to 1 to set aside an order by a federal judge in New York that would have stopped the bureau from reporting its 1980 findings to President Carter by midnight tonight, as required by law. The case now goes to the 2nd U.S. Court of Appeals.

Census figures are of major political and economic importance to state and municipal governments. Population determines how many representatives a state has in Congress, as well as the amount of federal financial assistance a community can expect.

The lower court order by U.S. District Court Judge Henry Werker came in response to petitions by New York state and city officials who charged that the 1980 count substantially underrepresented blacks and other minorities in their jurisdictions.

Bureau attorneys argued that Werker's ruling would "indefinitely delay the reapportionment of the next Congress." They took their "emergency appeal" to Justice Thurgood Marshall, who turned the matter over to the full court.

Marshall was the only dissenter in the decision, arguing that government lawyers failed to prove that delaying release of the census figures would cause "irreparable harm" to federal operations.

Instead, Marshall said, "The members of minority groups and other residents of low-income areas who were not counted by the Census Bureau will . . . suffer the irreparable injury stemming from the undercount."

Justice John Paul Stevens did not participate in deciding the case.

Yesterday's action sets aside Werker's order until the 2nd U.S. Circuit Court of Appeals can rule on the merits of the case. However, federal sources said they do not expect a decision soon.

Still, New York City officials took solace in the fact they will have another chance.

"We don't think it's in any way harmful to the ultimate resolution of this case," the Associated Press quoted David Jones, the city's adviser on census matters, as saying about the high court decision.

"I think we're going to prevail," he said.

Other cities complaining about alleged undercounts of their populations include Washington, Baltimore and Detroit, where a federal judge had ordered the bureau to delay its report to the president.Last week, Supreme Court Justice Potter Stewart stayed that ruling.

Legal challenges to the accuracy of the bureau's count also have come in 11 other states -- Colorado, Florida, Georgia, Illinois, Massachusetts, Minnesota, Missouri, New Jersey, New Mexico, North Carolina and Pennsylvania.

Yesterday's Supreme Court ruling does not affect those cases.

However, with the high court action, the bureau now may certify its 1980 state-by-state counts to the president. The agency also may report city and county totals to the individual states by April 1, barring further legal developments, for use in reapportioning state legislatures.