NEW YORK--New York City filed a formal challenge yesterday to the Census Bureau's headcount in the city in hopes of boosting the count--and preserving federal aid that's tied to population.

The 1990 Census missed as many as one million residents in its preliminary 1990 count of New York City's population, Mayor David N. Dinkins in announcing the challenge.

About 254,000 housing units, or one in 13, were skipped by census-takers, meaning they undercounted the city's population by 800,000 to one million, the mayor said.

The census bureau counted 7.033 million people, but the Department of City Planning estimates that eight million people live in the city.

The 1980 census placed the city's population at 7.07 million, and the census bureau later admitted it had missed about 450,000 people, Dinkins said. By 1987, the city had grown by another 280,000 people, he said.

The 1980 undercount cost New York City an estimated $675 million in lost federal aid over the next 10 years, and "the 1990 undercount could cost us up to $1 billion," Dinkins said.

"It is statistically stunning and demographically absurd for the Census Bureau to claim that a city whose resident birth rate has risen by at least 23 percent and which has welcomed more than 800,000 legal immigrants to its shores during the past decade has actually lost population," he said at a news conference.

Neighborhoods with minority populations tended to be undercounted by the bureau, said Richard Schaffer, director of the Department of City Planning.

The city was given 15 business days to review the bureau's 1990 preliminary figures. It did so by analyzing data from the city, Con Edison and the New York Telephone Co., as well as consulting surveys, atlases and aerial photographs.

In a letter to Sheila Grimm, regional director of the Census Bureau, Dinkins asked the bureau to review 11,900 city blocks--about 43 percent of the city's more than 28,000 residential blocks.

The bureau has said it would take 10 days to review the city's challenge.