China downgraded the announcement of an Airbus superjumbo order and signed up for the Boeing 747-8 as deals worth $9 billion coincided with a row over European emissions trading rules, industry sources said.

The deals both involved parts of the HNA airlines group and had been planned before the Paris Air Show, they said, but the decision not to announce the names of the buyers triggered one of the mysteries of this week's event.

Industry sources said plans to announce a high-profile $3.8 billion deal between Airbus and Hong Kong Airlines for 10 A380 superjumbos were called off on Thursday because of China's anger over European plans to charge airlines for emissions.

China threatened last month to hold back on purchasing Airbus aircraft because of the EU emissions trading scheme, which airlines body IATA has called illegal.

Additionally, industry sources said a company affiliated to the same carrier, Hainan Airlines, was behind the unexpected announcement of an anonymous deal at Boeing this week.

Boeing said an unidentified airline had provisionally committed to 15 747-8 passenger jets worth $4.8 billion.

Airlines often choose to buy jetliners without identifying themselves to their competition, but such announcements are rarely made at air shows which are designed for publicity. Boeing also rarely announces deals before they are confirmed.

Airbus and Boeing declined to comment and representatives of the HNA Group were not available.

Hong Kong Airlines is 46 percent owned by HNA Group, the parent of Hainan Airlines Co Ltd <600221.SS>.

TEMPTING TARGET

Airbus and Boeing both brought their largest passenger jets to the show, a biennial event which rotates with the Farnborough Air Show in Britain.

The 747-8 with 467 seats is Boeing's first stretched version of the 747 and is in the midst of flight testing. It will enter service initially as a freighter, then in a passenger version.

The 525-seat A380 is the world's largest airliner and Europe's most high-profile aircraft since Concorde, making it a tempting target in any political tensions affecting aerospace.

The Airbus deal has not itself been blocked and is in the manufacturer's order book, but the decision to cancel a signing ceremony is a clear protest signal, the industry sources said.

Aircraft purchases also need Chinese government approval.

The 747-8 purchase followed competition between Airbus and Boeing for the Hong Kong Airlines order.

While advancing development of its own smaller airplane, China tends to balance orders between the two foreign suppliers.

From Jan 1 next year, the EU will require all airlines flying to Europe to be included in the Emissions Trading Scheme (ETS), a system that compels polluters to buy permits for each tonne of carbon dioxide they emit above a certain cap.

China's top aviation industry body ramped up pressure on the European Union earlier this month, saying it would give full support to legal action against the forced entry of airlines into the EU's carbon trading scheme. [ID:nL3E7H60D5]

China says the scheme is unfair for developing countries and costly.

(Additional reporting by Matthias Blamont; Editing by Jon Loades-Carter)