While the nation’s housing sector is getting whacked by slowing sales, falling prices, and rising inventories, several pros tell me New York City’s market is on a tear again. The facts bear this out.

About two weeks ago, a couple who owned a two-bedroom Manhattan apartment at 400 E. 51st St. put it up for sale at $1.599 million, which was around the going price in the building for that size apartment. They quickly got four offers, three at the asking price. The apartment sold a few days ago, for $1.65 million.

The real estate broker who represented the seller, Elayne Reimer of Coldwell Banker, explained the higher price. “Bidding wars are back,” she said. “This business has never been better, nothing decent stays on the market very long, and there isn’t a bad housing area in Manhattan.”

The broker credited much of the strong sales to this year’s record Wall Street bonuses (an estimated $24 billion) and the fact that, unlike in years past, many retirees are in no rush to live elsewhere.

Ms. Reimer, who sold the East Side apartment Mayor Giuliani occupied when he was separated from his wife, compared the vigor of the city’s housing market with the booming years of 2004 and 2005, when Manhattan apartment prices surged 19% and 22%, respectively.

“We’re back in boom times,” Ms. Reimer said, noting the prices of apartments she’s selling are up about 20% from last year. A year ago, she said, the bulk of her sales ranged between about $700,000 and $2 million; now it’s between $1 million and $3 million.

Ms. Reimer noted that almost nothing is going below the asking price unless it’s ridiculously overpriced. In the past, many would-be buyers would automatically underbid the asking price by about 10%. That practice, given the strength of the market, is rapidly becoming history, she said. “The key is the rising price trend in Manhattan is back and the clear direction is up,” she said.

Another broker, Vicki Gershwin of Brown Harris Stevens, echoed Ms. Reimer’s sunny assessment. “Housing is crazy right now; it’s on fire,” she said. “Even the dogs are being snapped up. Demand is exceptionally strong and making matters worse, there’s practically no inventory around.”

Ms. Gershwin estimated apartment prices are up between 6% and 10% versus a year ago. She also noted that bidding wars are back, and added that any broker who has an exclusive listing is being bombarded by other brokers seeking to show it. The most noteworthy trend, she said, is the increasing demand for larger apartments, notably four bedrooms and up.

“We’re seeing a very high level of volume” across-the-board, the president of real estate appraiser Miller Samuel, Jonathan Miller, said, estimating that 2007 prices would be up 5% to 10% versus the same period a year ago. Pointing to fairly flat inventories, Mr. Miller figures the current sales pace has the makings of a record spring season. Everything is coming together for the industry, he said, pointing to a solid economy; another likely strong year of Wall Street bonuses; a weak dollar that is spurring foreign demand, and low mortgage rates.

If you have deep pockets and crave a large luxury apartment, a couple of listings might strike your fancy. One is a penthouse duplex at 1026 Fifth Ave., replete with 16 bedrooms, terrace views of Central Park, and five working fireplaces. The asking price from the owner, the Kress family, which owned the Kresge store chain, is $50 million. Maintenance is $15,000 a month. However, the apartment needs an overhaul that will likely run an additional few million dollars.

The other luxury residence — at 834 Fifth Avenue — is owned by Lioda Lewis, widow of Reginald Lewis, former head of Beatrice Foods. The 15-room apartment, which has three maids’ rooms and 7 1/2 bathrooms, runs $39.5 million. Maintenance is $17,000 a month. If you’re bored and would to like to learn about the publishing business, you can always ring the doorbell of a neighbor, Rupert Murdoch.

To get the green light to buy either of these ritzy apartments is no easy task, according to Denise Lefrac Calicchio, author of “High Rise Low Down,” an incisive insight into the city’s residences of the rich and famous. Aside from big bucks, she said, “ultra-exclusive boards will require you to have the right references, the right credentials, to be a member of the right clubs. and to have gone to the right schools.” Ms. Calicchio has no doubt both apartments will be sold because, as she put it, “the real estate business here is roaring.”

dandordan@aol.com