The new Airbus 380 "Superjumbo" has just completed its maiden commercial flight and there are already plans to transform the world's largest passenger plane into the pinnacle of private luxury - an executive jet.

Two European companies - Germany's Lufthansa Technik and Switzerland's Jet Aviation - have announced their intention to convert the enormous airliner into a flying mansion replete with private bedrooms, a movie theater, and a gym fitted with saunas and jacuzzis.

Media reports in Europe have said Lufthansa Technik, a subsidiary of Deutsche Lufthansa, recently received an order for a VIP-configured A380 from Russian billionaire Roman Abramovich.

Both Abramovich - who in 2005 acquired a specially modified Boeing 767ER - and Hamburg-based Lufthansa Technik have denied the reports. But a Technik spokesman said they were expecting a firm order for the A380 from a different private customer.

"There is definitely a market for an executive version of the Airbus 380," said Bernd Habbel, Technik's head of corporate communications.

Purchases of private airliners have hit record highs, with manufacturers set to deliver more than 1,000 planes this year, and industry experts predicting sales of US$200 billion over the next decade.

But most of those planes are relatively small, in the short-haul category of a Learjet, Cessna Citation or Gulfstream, and usually costing US$2 million to US$5 million. The largest corporate jets are usually modified versions of the Airbus 320 or Boeing 737 that sell for about US$70 million.

Experts say only national governments and very few of the super-wealthy can afford massive price tags that come with the higher category, such as a Boeing 767 that is three times the size of an average executive jet.

The market is also seemingly immune to the financial turbulence that has gripped global markets, too.

"Limousines or extravagantly tricked-out yachts are frequently fitted with plush custom-made interiors," said Richard Maslen, an editor of Airliner World, a British aviation magazine. "The world of aviation is no different - 'customized' aircraft have long been available for those who can afford them, such as royal families, heads of state or the growing coterie of billionaires."

He added: "Anyone who wants to customize their mode of travel to accommodate lots of friends - or perhaps adapt it to withstand a terrorist attack - will find that there are companies prepared to take on the work."

But the 560-tonne A380 is in a size category of its own, dwarfing even the Boeing 747, which serves as America's presidential Air Force One jet.

Technik has drawn up a general design for a customized luxury A380 interior, although a customer would collaborate on specific details, Habbel said.

A rendering of the layout provides the owner with two spacious private bedrooms on the upper deck, separated from a reception area with plush sofas and a wood and brass bar next to the central stairway.

The private quarters allow for maximum comfort and convenience. A master bedroom includes an office, private dining room, dressing room, a fully fitted bathroom and a gym featuring both a steam bath and exercise machines.

The entourage is accommodated in lounge-type quarters on the lower deck, also equipped with a large dining and conference area. There is a third level, the cargo area below, that can be transformed into yet another passenger space or a cinema if needed.

And what would the price tag be of a custom-fitted Airbus 380?

Technik is reluctant to discuss the cost. But according to Airbus spokeswoman Maggie Bergsma, the list price of an A380 is US$320 million. Experts say customized furnishings can rack up an additional US$50-$150 million, as the degree of luxury depends entirely on the depth of the buyer's pockets.

Basel-based Jet Aviation has already received four letters of intent for the yet-to-be-delivered 787 Dreamliner, the newest jet of Boeing.

"We will certainly be one of few players that can do the completions on an A380 for whoever wants to do that," said Heinz Aebi, a company vice president.

Jet Aviation delivered two Boeing 747s converted to luxury standard for Dubai Air Wings this year.

"There will always be customers who want such planes that can fly intercontinental ranges without the need to land and refuel," Aebi said.