NEW ORLEANS (AP) — Federal public housing officials have signed off on the planned demolition of the city’s four largest housing complexes, the Housing Authority of New Orleans announced Friday.

In approving HANO’s application for the widespread demolition, the U.S. Department of Housing and Urban Development legally protected housing vouchers for thousands of poor families who once lived at the city’s largest developments until they were forced out by Hurricane Katrina in August of 2005.

The move also protected $34 million in tax credits HANO received to use toward revamping its housing stock.

The government’s Disaster Housing Voucher program was slated to end soon, but because HUD has paved the way for demolition, HANO tenants will not lose any benefits. Instead, families will be eligible for the ‘‘Tenant Protection Voucher’’ program, worth $7 million in rents this year and $30 million for 2008.

‘‘These tenant protection vouchers are good until new housing is built,’’ HUD spokeswoman Donna White said.

Not everyone was pleased by the news, however.

U.S. Sen. Mary Landrieu, D-New Orleans, protested, saying the structures should remain standing until more specifics of what will replaced them have been decided.

‘‘To announce demolition, which could begin as early as November, without sufficient planning in place seems irresponsible,’’ Landrieu wrote. ‘‘This action will only serve to deepen the ongoing affordable housing crisis for my constituents most in need and further increase distrust in the community’’ with the Housing Authority of New Orleans and HUD.

Developers are begin tearing down a total of 4,500 units at the aging brick buildings across the city within two to three months, making way for the massive rebuilding project of what has been termed ‘‘mixed income’’ housing.

White stressed the citywide demolition of public housing had begun long before Katrina stuck. The Guste in Central City and the Fischer in Algiers already have been transformed into modern-day housing.

‘‘Katrina just sped things up,’’ White said.

HUD announced in June that it would do away with the so-called ‘‘Big Four’’ developments, C.J. Peete in Central City, St. Bernard in the 7th Ward, B.W. Cooper off Martin Luther King Boulevard, and Lafitte, which borders the historic Treme neighborhood.

Those complexes have been mostly empty since the storm as HANO has fought off a lawsuit seeking to preserve them.

HANO has returned 1,600 families to public housing complexes, which were home to 5,100 families before Katrina struck two years ago. The agency has promised to re-open 3,000 units of public housing by the year’s end.

This week, HANO made plans to re-open 94 units in 18 buildings at the Lafitte, along with about 100 additional apartments at the B.W. Cooper, which re-opened to families late last year.

‘‘We are still a ways from actual demolition,’’ said Donald Babers, the board chairman for HANO. ‘‘This is not happening next week.’’

Awaiting wrecking crews are 4,500 units of public housing at the four complexes. After all redevelopment is complete, developers will have created 7,000 homes across New Orleans, including 3,300 homes reserved for public housing families and 1,800 available for families using federal housing vouchers or tax credits. The rest will be market-rate rentals and homes for sale.

HANO officials said the demolition will be done in phases to ensure the safety of public housing tenants who will be living at the complexes while their neighborhoods are transformed.