(May 27): China has been slow-walking approval of Airbus SE plane deliveries to signal impatience with how long European regulators are taking to certify Chinese-made aircraft, according to people familiar with the matter.

For the past several months, the Civil Aviation Administration of China has delayed the final approval that allows Airbus jets to enter the country and be put into service, said the people, asking not to be identified discussing confidential information.

Airbus delivered its fewest commercial jets in the first quarter since 2009, and the company said that was partly due to an “administrative” issue that halted delivery of almost 20 aircraft to China.

Airbus chief executive officer Guillaume Faury predicted last month that deliveries would be back on track by the end of June, declining to elaborate further. The France-based planemaker delivered only 16 aircraft to Chinese airlines in the first five months of this year, compared with 47 through May last year, according to data compiled by Cirium.

State-run Commercial Aircraft Corp of China, known as Comac, is seeking to get its C919 model certified for the first time outside Asia. The model, which relies heavily on Western technology for its engines and aeronautics, competes with Airbus’s A320 and the Boeing Co’s 737.

The certification of a brand-new aircraft type usually takes many years, but Comac is aiming to complete the process on an abridged timeline. The decision will be made by the European Union Aviation Safety Agency, or EASA.

If tensions over Comac persist or even escalate, it could put at risk Airbus’s lead in the world’s second-largest aviation market. China is the largest customer for Airbus in terms of fleet, and the European planemaker expects China to take delivery of about 9,570 new aircraft during the next 20 years, according to a long-term projection by the company.

Airbus referred to previous comments by Faury calling the hiccup an administrative issue that’s been resolved. EASA didn’t reply to an email seeking comment. CAAC and Comac didn’t respond to faxed requests for comment.

The C919, which seats as many as 192 passengers, is crucial to China’s ambitions to muscle its way into the global commercial jetliner duopoly between Airbus and Boeing. The market that the aircraft addresses is by far the biggest segment of the industry, and gaining certification in the West would give Comac the ability to market the plane to airlines around the world. The model is currently only operated in China.

Boeing has also struggled in China. While the company secured a long-awaited order during US President Donald Trump’s visit to Beijing earlier this month that ended an almost decade-long drought of purchases by Chinese airlines, it was for a smaller number of planes than previously expected.

The jockeying over aircraft certification has precedent. Earlier this year, Trump threatened to impose a 50% tariff on planes from Canada sold in the US and decertify all new planes made there until Ottawa agreed to approve certain jets made by Gulfstream, a unit of General Dynamics Corp.

Weeks later, Canada’s aviation regulator certified the remaining Gulfstream private jet models.

Uploaded by Magessan Varatharaja