JUST PLANE DESPICABLE

Beleaguered Citigroup is upgrading its mile-high club with a brand-new $50 million corporate jet - only this time, it's the taxpayers who are getting screwed.

Even though the bank's stock is as cheap as a gallon of gas and it's burning through a $45 billion taxpayer-funded rescue, the airhead execs pushed through the purchase of a new Dassault Falcon 7X, according to a source familiar with the deal.

The French-made luxury jet seats up to 12 in a plush interior with leather seats, sofas and a customizable entertainment center, according to Dassault's sales literature. It can cruise 5,950 miles before refueling and has a top speed of 559 mph.

There are just nine of these top-of-the-line models in the United States, with Dassault's European factory churning out three to four 7Xs a month.

Citigroup decided to get its new wings two years ago, when the financial-services giant was flush with cash, but it still intends to take possession of the jet this year despite its current woes, the source said.

"Why should I help you when what you write will be used to the detriment of our company?" replied Bill McNamee, head of CitiFlight Inc., the subsidiary that manages Citigroup's corporate fleet, when asked to comment about the new 7X.

"What relevance does it have but to hurt my company?"

It's not uncommon for large companies to pay a deposit on a new plane then cancel the order before delivery, according to a source in the corporate aviation business.

Citigroup execs are also quietly trying to unload two of their older Dassault 900EXs.

Those jets, nearly 10 years old, are worth an estimated $27 million each. They were still listed for sale yesterday on the Web site of Citigroup's aviation broker, Aviation Professionals.

A company representative said she would not comment on "brokering both sides of the deal" when asked about the incoming Falcon 7X.

The Dassaults are part of CitiFlight's Gulf Sierra fleet, which includes the two Falcon 900EXs, tail numbers N399GS and N588GS, currently for sale. FAA records show Citigroup reserved a new tail number, N488GS, possibly for the incoming 7X on Nov. 10 last year.

A woman answering the phone at CitiFlight's private hangar in White Plains said she was "not authorized to release information" about the new jet.

Dassault's US sales office declined to comment.

Citigroup spokesman Stephen Cohen declined to comment.