People visit the 50th International Paris Air Show at the Le Bourget airport in Paris, France, June 17, 2013. The Paris Air Show runs from June 17 to 23. (Xinhua/Gao Jing)

The 2013 International Paris Air Show kicked off here on Monday, with world aviation industry heavyweights Airbus and Boeing declared big orders on the first day.

As the leading European airplane manufacturer, Airbus opened the day by announcing the order made by the Doric aircraft financing group, a leasing company which serves airlines such as Emirates and Singapore Airlines. The group offered a provisional order of 20 superjumbo A380 airliners with a catalogue price of 8 billion U.S. dollars.

Airbus also confirmed that International Lease Finance Corporation (ILFC), the biggest customer of Airbus, had made a firm order for 50 short-haul A320neo jets, a more fuel-efficient model than the much popularly used A320, at list price of 5 billion dollars.

The airplane manufacturer's another customer was German airlines Lufthansa, which had confirmed its order in March for 100 A320, worth 10 billion dollars at list price.

Meanwhile, Boeing is getting purchase commitment of the leasing company GE Capital Aviation Services (GECAS) to buying 10 of its next-generation Dreamliner 787-10 planes for 2.9 billion dollars.

As Boeing's new customer of medium-haul plane, Japan's Skymark Airlines said it had put in order for four 737 MAX airplanes with a cost of 402 million dollars.

Besides, Qatar Airways has extended two firm orders and seven option orders for Boeing of nine of its long-haul 777-300ER planes with a total value of 2.8 billion U.S. dollars at catalogue price.