WASHINGTON — The nation's inner-ring suburbs, faced with deteriorating roads, expensive housing and increasingly diverse populations, "are staring down a set of looming challenges" that threaten their stability, according to a report released Wednesday.

The report, by the Brookings Institution, notes that nearly one-fifth of America's population lives in what it calls "first suburbs," the cities and towns adjacent to inner cities.

They lie between the country's fast-growing outer suburbs and slow-growing or declining inner cities and are often neglected by both urban and suburban policies, the report says.

"Unfortunately, the interests of first suburbs appear underrepresented at the federal and state level," the report says. Such suburbs "often remain absent from larger coalitions that represent the broad interests of municipalities or, if they are represented, they are lumped in with larger 'suburban' interests."

"Politically, they are less than the sum of their parts," said Bruce Katz, director of the Metropolitan Policy Program at Brookings.

The program hosted a symposium on first suburbs Wednesday featuring county leaders from the metropolitan areas of Seattle, Pittsburgh, Dallas, New York and northern Virginia.

The leaders complained that their communities face many of the social and economic problems of larger cities, but get fewer resources to address them. Federal housing programs neglect the need for affordable housing in inner suburbs, the leaders said.

"We are watching all of the money go to primary cities," said Dallas County Judge Margaret Keliher.

"When people say to me, 'Why does the city of Dallas handle all of the homeless?' I say it's because the city of Dallas gets all of the money," Keliher said.

The study identified 64 counties across the country as homes to first suburbs and analyzed demographic changes in those counties from 1950 to 2000.

Such suburbs still have high levels of home ownership, household income and education attainment, but those achievements are in jeopardy, the report said.

Among the findings:

—While concentrated poverty is on the decline nationally, it is increasing in first suburbs.

—Overall household incomes increased nationally in the 1990s, but declined in first suburbs.

—The share of racial and ethnic minorities living in first suburbs more than doubled from 1980 to 2000. Minorities now make up one-third of their populations.

Rep. Michael Turner, R-Ohio, told the audience at Brookings that House Republicans have formed a working group to address the needs of cities and inner ring suburbs.

Turner said he is promoting a bill that would offer tax breaks to developers who clean up and build on contaminated sites in cities and inner-ring suburbs.

On The Net: The Brookings Institution: www.brookings.edu/index.htm