Airbus announced its first big deal of the year and Boeing saw better times ahead, despite the dire climate for the aviation industry at the opening of the Paris Air Show on Monday.
"It feels to me that we may have reached the bottom," Scott Carson, head of commercial airline business at US jetmaker Boeing, told reporters at the show.
"There is no certainty. But it does feel to us that there are reasons to hope that the recovery will begin next year," he added.
Boeing's bitter European rival Airbus also sounded an upbeat tone, announcing an order from Qatar Airways for 24 medium-haul A320 airliners.
"Qatar Airways has signed a firm contract for 24 Airbus A320," it said.
Italian aerospace giant Finmeccanica's chief executive Pier Francesco Guarguaglini also said he saw "signs of recovery" in economic activity and added: "If the crisis does not last, the negative impact will be limited.
The Paris Air Show opened in driving rain and a downbeat mood after a collapse in air travel owing to the global economic crisis and concern about safety issues after the mysterious crash of an Air France Airbus in the Atlantic this month.
The week-long show at Le Bourget near Paris celebrates its 100th anniversary this year. Organisers said there were a record 2,000 exhibitors despite the slump and they forecast that visitor numbers would stay the same.
"This... air show is overshadowed by two events," Airbus head Thomas Enders told a seminar here, recalling the still unexplained June 1 loss over the Atlantic of an Air France Airbus A330 and the deep financial crisis.
The International Air Transport Association says the airline industry could lose 9.0 billion dollars (6.4 billion euros) in 2009 because of falling demand and rising oil prices -- almost double an estimate made three months ago.
Louis Gallois, head of the European Aeronautic Defence and Space Company (EADS), Airbus' parent company, said: "This will not be an air show of orders."
Enders said that while Airbus still hoped to receive about 300 orders this year the final tally "could be considerably lower."
Two years ago -- well before the global recession and a spike in oil prices in 2008 -- the world's top manufacturers Airbus and Boeing won a total 800 orders worth more than 100 billion dollars (71 billion euros).
The companies are long-standing rivals and their competition in dominating the world market for airliners is usually one of the main features at Le Bourget. But this is overshadowed this year by the crisis hitting aircraft makers around the world.
Excluding the Qatar Airways order announced on Monday, Airbus so far this year has received a total of 11 net orders after 21 cancellations on 32 gross orders and Boeing has seven net orders after 66 cancellations on a total 73 orders.
Shares in EADS have fallen 8.06 percent this year however, while Boeing stock has risen by 20.55 percent. Since the Air France jet crash on June 1, EADS stock has dropped 0.69 percent and Boeing shares have risen 14.64 percent.
"Priority number one is to secure deliveries and support our customers," Enders said, stressing that 2010 and 2011 would be critical years for the airline sector as it struggles to overcome the impact of global recession.
In addition to questions raised by the loss of the Air France jet, which took the lives of all 228 board, Airbus must also contend with major delays and potential funding problems for its A400M military transport plane.
Clients signed up so far for the A400M are Belgium, Britain, France, Germany, Luxembourg, Spain, Turkey, some of whom have threatened to abandon the 20-billion-euro deal, forcing EADS to re-negotiate delivery schedules.
France also argued for advance state financing for the Airbus A350 project from EU partners, saying such funding did not break European Union rules on state aid as ministers from Britain, France, Germany and Spain met at the show.
Boeing too has encountered development problems and delays with its long-haul, fuel-efficient 787 Dreamliner, although company officials now hope to see the aircraft make its first test flight before the end of the month.