European plane maker Airbus kept ahead of its US rival Boeing on Wednesday in the order tally at the Farnborough International Airshow, where leasing companies and Asian and Middle Eastern airlines have been top customers. Airbus increased its score for the show's first three days to 233 after South Korea's Asiana Airlines announced a deal for 30 of its medium capacity, long-range A350 XWB jets for a catalog price of $7.2 billion (£4.5 billion) before discounts. The airline also took an option for another ten A350 jets. Boeing brought its tally to 152 by early afternoon Wednesday after leasing company Aviation Capital Group said it has ordered 15 next-generation Boeing 737-700s is worth around $934 million at list prices. Boeing boosted its air show tally by including an order for 35 737-800s from Malaysia Airlines that had been already been registered in its books as an unidentified order for several weeks. The order was valued at more than $2.6 billion (£1.63 billion) at list prices, and including purchase rights for 20 more aircraft. The Boeing air show score did not including an order from Air China Ltd. for 45 jets with a list price of $6.3 billion (£3.94 billion) that was announced away from the airshow. Middle Eastern carriers and aircraft leasing companies have so far made the biggest orders at the show outside London as soaring oil prices and anticipated decreased passenger demand thanks to credit crisis leaves many US and European airlines cash strapped. Plane makers, however, have been talking up the prospects of the current financial outlook to push forward an industry shift toward cleaner, more efficient planes. Aviation currently produces 2 percent of global man-made carbon dioxide emissions, a figure that is forecast to rise to 3 percent by 2050. Boeing Co. has touted its 787 jet for its greater fuel efficiency, although the plane has been hampered by delays that have cost the company credibility and billions of dollars in expected additional costs and penalties. Boeing on Tuesday said 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. Boeing has picked up a number of orders for the plane at Farnborough, including a deal for 35 of the aircraft from Etihad Airways, the state carrier of the United Arab Emirates. Etihad has made the biggest order by an airline so far at Farnborough, splitting an order for 100 aircraft between Airbus and Boeing worth $20 billion at list prices. Leasing companies Aviation Capital Group and a unit of Dubai Aerospace Enterprise announced deals on Tuesday for a combined 123 aircraft. In the current climate carriers are more likely to rent than buy their own planes. Other deals have been signed by Qatar Airways, FlyDubai, Saudi Arabian Airlines and Arik Air since the show began on Monday. At the Paris airshow last year, held every other year in alternation with Farnborough, 506 orders were taken between Airbus and Boeing. Almost 1,500 exhibitors from 35 countries are showing off the latest in aviation technology at Farnborough. The air show runs through July 18 for aerospace professionals only; public days are July 19 and 20.