The Champs-Elysees lures millions of tourists every year to enjoy shopping at the Elysees 26 mall, poker at the Aviation Club, plush cars and futuristic architecture in the Citroen showroom or the show at Lido.

But for all their Parisian charisma, none of these attractions are French-owned. They belong to the royal family of Qatar, a resource-rich emirate about 5,000 km away.

Over the past few decades the buildings have helped bolster Qatar's global portfolio of trophy assets, including London's Harrods and Singapore's Raffles Hotel.

The latest French addition was a chain of upscale malls under the Printemps banner, bought by a fund controlled by Qatari royals in August for 1.7 billion euros ($2.23 billion).

For royalty from the Gulf, part of the attraction of the United Kingdom has been the fact it charges no taxes on profits foreign investors make when they sell real estate.

Five years ago, Qatar sealed a similar agreement with France. The treaty was agreed by former centre-right president Nicolas Sarkozy in 2008, and is one of the most generous Qatar has secured, exempting Qatari investors from taxes on the profits they make when they sell properties.

In a country where 3.6 million people lack decent housing, according to Abbe Pierre, a charity, that is controversial.

Politicians, including some in Francois Hollande's new Socialist government, have been critical. In April budget minister Bernard Cazeneuve called the treaty "an exception that we do not wish to duplicate." Others have asked if the accord brings economic benefit to compensate for the lost tax revenue.

The government has said it is examining the treaty, but an official at the French finance ministry told Reuters that Qatar's purchases don't have to be declared, so it is impossible to see how much tax is at stake.

A Reuters examination of regulatory filings, court documents and other data sheds new light on Qatar's property assets. Reuters mapped around 40 properties in France that are owned by Qataris, a total investment of 5.9 billion euros ($7.8 billion) over the past decade, including 4.8 billion since 2008. At current values they would be worth around 6.3 billion euros.

The Qatari state and its sovereign wealth fund owns about a dozen of the properties, together worth around 3 billion euros, Reuters found; the rest belong to members of the ruling Al-Thani family.

A personal fund set up by Sheikh Hamad bin Khalifa Al-Thani, the previous emir, controls about nine of them; his children, including the current emir, six. The rest were bought either by other relatives, or businessmen with strong ties to the Al-Thanis, such as Ghanim bin Saad al-Saad.

Each property is owned by a holding company that is itself held by one or more entities, some of them outside France. This makes it hard to track when properties change hands, to see how much tax the French have forgone with the deal.

If there had been no treaty, though, market values at the end of 2012 suggest the French government would have collected at least 145 million euros in tax if the entire portfolio were sold and taxed at the lowest applicable rate, according to Reuters calculations which were assessed by three experts.

While that's less than a day's gas export revenues for Qatar, in France it would equate to a year's pre-tax pay for some 4,500 schoolteachers or nurses, said experts.

The Qatari authorities and the sovereign wealth fund Qatari Diar did not respond to questions. Chadia Clot, whose company French Properties Management handles private investments made by the al-Thani family, too did not respond.

Gilles Kepel, a professor at the Paris Institute of Political Studies, said Qatar's financial gains symbolise how the emirate has gained influence by spending its resource wealth, but has also triggered friction.

"Qatar has had a full-speed-ahead investment strategy in France, forged under the previous French administration," said Kepel. "But this has led to antagonism."

In 2008, a report for the French parliament praised the tax arrangement for encouraging Qatari investment in French real estate which "can only benefit the French economy." The treaty has several clauses to promote the exchange of information and prevent abuse, and France has similar arrangements with other rich oil states such as Kuwait and Saudi Arabia.

Qataris have been particularly active since the deal was sealed. From the Virgin Megastore flagship to the Hotel Martinez in Cannes, from soccer club Paris Saint-Germain to farmland in Normandy, Qatari royals have acquired dozens of properties.

"It is thanks to these tax advantages that the Qataris are the only ones buying French property at the moment," said Philippe Chevalier, head of French real-estate broker Emile Garcin. "I would support more of these advantages."

The treaty allows state-owned Qatari entities to avoid capital gains tax - the lowest rate would be 34.4 per cent - on any profits made selling French property, whether held directly or via subsidiary companies. Private Qatari investors are entitled to the break as long as they hold the property in an investment vehicle that also has 20 per cent in non-property assets. The treaty applies to all purchases made since January 2007.

Buoyed in part by Qatari investors, Paris luxury property prices have risen by approximately 14 per cent since 2008, according to data for the highest-priced residential bracket tracked by real estate analysts Investment Property Databank (IPD).

France may have caught up with Britain in attracting Qatari investments, according to data from research firm Real Capital Analytics (RCA) on the UK commercial property market.

Qataris have spent about 4.5 billion euros ($5.9 billion) on publicly disclosed commercial and development sites in the UK since 2008, the data shows.

Keeping up with the British was, say former French trade officials and policy analysts, one reason to agree the treaty in the first place. In 2008, oil producers were riding a boom in commodities just as centres like London, New York and Paris took a hit from the financial crisis. Many Western capitals were keen to capture investment: Paris was promoting Islamic finance, and saw the deal as a way to spur growth.

"What this treaty does is effectively put Paris on a level playing field with London - just not for everyone," said John Forbes, a London-based real-estate consultant.

Aside from the United Kingdom, only Ireland has offered Qatar the same exemption and that only since 2012, a review of more than a dozen of the emirate's bilateral tax treaties shows. At home, Qataris face no personal income taxes but some businesses could be taxable at up to 10 per cent on gains from the sale of property.

"The exemptions ... are on the generous side, even by the standards of other French treaties," said Charles Beer, the managing director at consultancy Alvarez & Marsal. "This level of treaty exemption is rare, if not unknown, in other countries' treaties."

Just a stone's throw from the Champs-Elysees, the magnificent Peninsula Hotel shows how the treaty - which was an update of a pact dating back to 1990 - favours Qatari investors.

Promising a "new level of distinction" for the Paris luxury hotel market, for the time being the hotel is hidden behind scaffolding and a corrugated-iron fence. It's due to open in 2014 after a six-year renovation project.

It was originally a business centre owned by the French state, which collected 460 million euros when it sold it to a Qatari bank in 2007. The property was later transferred to a Qatari sovereign wealth fund focused on hotels.

After the initial sale, the valuation rose. In 2009, it hit 500 million euros when China's Hong Kong and Shanghai Hotels (HSH) said it had bought a 20 per cent stake in the project for 100 million euros. At end-2012 market prices, the whole building was worth an estimated 550 million euros, based on IPD data.

If HSH had sold out then, it would owe at least 3.4 million euros in taxes on a capital gain of 10 million. Qatar, meanwhile, would face no tax at all on its much bigger capital gain of almost 80 million euros, according to the treaty.

A spokeswoman for HSH declined to comment beyond saying the company followed all tax laws and had no intention of selling the Peninsula stake; it is a "long-term investment." Qatari representatives did not respond.

Property experts say the luxury real-estate deals that are encouraged by the tax treaty mainly benefit a small circle of investors.

"We are always told this type of agreement is designed to promote investments in France but this is money that is not going into the economy," said Olivier Duparc, a Paris-based notary. "Taxes are going up for everyone except the Qataris, it seems."

In offices overlooking the Place de la Concorde, where revolutionaries guillotined aristocrats in the 1790s, Syrian-born Guy Delbes runs property company Elypont, which manages several French assets on behalf of Qatar's sovereign wealth fund.

He points out that Qatar's tax advantages are on a par with those given to some other Middle Eastern investors in the 1980s and 1990s. "The notion that Qatar has advantages that other countries do not" is wrong.

Indeed, a 2009 report by the Senate showed Kuwaiti state-owned entities are also exempt from capital gains tax on property, while Saudi Arabia has been given similar, though fewer, advantages.

However, Kuwait has not made any commercial property acquisitions in France since 2007, according to RCA, which compiles data only on commercial property. Saudi Arabia bought over 900 million euros of commercial property in the same period, RCA research shows.

Buyers from both states have made other investments, particularly in residential real estate, that have not emerged in public. But real-estate agents say they are not as active as the Qataris, and regulatory filings yield little information on private investments.

These include a luxury home opposite the Eiffel Tower owned by the late Saudi Crown Prince Sultan bin Abdulaziz al-Saudi and a Kuwaiti family's flats near the Avenue Montaigne.

The French finance ministry said it can't count Saudi Arabia and Kuwait's tax-free purchases because, like Qatar's, they are not declared. Government officials from Saudi Arabia and Kuwait declined to comment.

Some French lawmakers suggest the Gulf nations are even competing for French tax concessions: Qatar used the Kuwaiti precedent to renegotiate its treaty in 2008 and today the UAE is using Qatar's to pressure the French for the same sort of gains.

"The UAE is not at all happy because Qataris have a better tax treatment," remarked Nathalie Goulet, a centrist senator from Lower Normandy, who spoke to the UAE officials during a fact-finding mission to the Gulf earlier this year.

She finds the French concessions "extravagant" and says the fact that Qatar's neighbours are complaining is a sign the treaty is wrong. "Our deficit has destroyed our freedom," she said. "The Qataris are here to buy, whilst we are selling our family jewels."

UAE Finance Ministry Under-Secretary Younis Haji al Khoury said Qatar's tax treatment in France was a matter for those two countries. Asked whether the UAE was seeking renegotiation, he said: "We have not yet negotiated these terms. This is an internal matter and we'll do it in due time if we need to." The French ministry said its priority would be to improve exchange of information.

Taxes matter a lot in France: The country's total tax take was 43 per cent of GDP in 2010, according to the Organisation for Economic Cooperation and Development (OECD), far bigger than the US (25 per cent) or the UK (35 per cent).

A generous healthcare system and faith in the state have helped governments sell tax rises to the public, which are needed to trim a 90-billion euro budget deficit. -Reuters