European plane maker Airbus booked orders for 143 planes Tuesday at the world's biggest air show, while Boeing Co. reassured the industry that its previously delayed 787 jetliner remains on schedule. In other deals on the second day of the Farnborough International Airshow, Boeing booked orders for seven planes, while Russian aircraft maker Sukhoi sold 24 of its Superjets. Airlines from Middle Eastern countries have saved the Farnborough International Airshow from an otherwise lackluster start, signing orders for around 150 planes worth more than $25 billion on Monday. Many European and US airlines are struggling to cope with rocketing fuel prices and dampening passenger demand, combined with tighter credit conditions. In contrast, several Middle Eastern carriers with the benefit of oil-backed sovereign wealth funds are banking on anticipated huge investment and greater tourism in the Gulf region to justify spending at a time when there is talk in the industry of potential cancellations and delays on existing orders. “We carriers from the Gulf are the center of attraction these days,” said Qatar Airways CEO Akbar Al-Baker as he announced an order for four A321s worth $360 million (£227.17 million) at list prices to a packed room of journalists. The Qatar deal, which includes options for another two single-aisle A321s, was followed by an announcement by Tunisair for 16 Airbus jets worth $1.94 billion (£1.22 billion). The Tunisian carrier firmed up an order for the purchase of 10 single-aisle A320s, three wide-body A330s and three of the revamped, long-range A350-800 XWBs. The deal had already been announced in April after Tunisair gave a “letter of acceptance” to Airbus. In a further deal for Airbus, the aircraft leasing arm of state-owned Dubai Aerospace Enterprise confirmed Tuesday a firm order for 100 Airbus planes worth $12.6 billion (£7.88 billion) at list prices. DAE Capital's order for 30 wide-bodied A350-900 and 70 single aisle A320s follows a memorandum of understanding signed at the Dubai air show in November 2007. Rounding out the Airbus deals, US leasing firm Aviation Capital Group announced that it has signed a firm order for 23 Airbus A320s valued at $1.8 billion (£1.13 billion) before discounts. Boeing announced an order from Nigerian carrier Arik Air for seven next-generation 737s, adding to its existing order of 10 of the aircraft. Arik Air also announced its intent to purchase four Boeing 747-8 Intercontinentals, but the order will not be added to the plane maker's order book until final contract negotiations are completed. Sukhoi booked orders from Avialeasing for 24 of its Superjet 100 aircraft worth more than $630 million and took an option for 16 additional aircraft. Sukhoi said ahead of the show it expected to book orders for 30 Superjets. The United Arab Emirates sought to move deeper into commercial aerospace through a deal Tuesday between the aerospace division of Abu Dhabi investment fund Mubadala Development Company and Airbus parent EADS to produce and supply parts for Airbus. The plant will start operations in 2010 initially making wing components, with the intention to eventually develop and design larger composite structures. EADS CEO Louis Gallois hailed Mubadala's “ambition to become a major player in the highly technological aerospace industry. “It's a region which is buying a lot of planes and which wants to develop its industry: we have to be there,” he told The Associated Press. Airbus' rival Boeing Co., who inked deals for 95 aircraft on Monday, said Tuesday it remains on track to test fly its 787 jetliner in the fourth quarter of this year and make its first delivery in the third quarter of 2009 - but acknowledged that its timetable remains tight. Program manager Pat Shanahan said the Chicago-based plane maker was working to fix a recently discovered brake problem that is key to the aircraft receiving hardware qualifications in the next month or so. The 787, touted by Boeing for its greater fuel-efficiency potential, has been hampered by delays that have cost the company credibility and billions of dollars in expected additional costs and penalties. Etihad Airways on Monday when it split an order for 100 aircraft between Airbus and Boeing worth $20 billion at list prices.