FARNBOROUGH (Reuters) - U.S. aerospace giant Boeing Co BA.N could generate more than 40 percent of its defence sales from international customers in a decade, the head of international sales told Reuters.

FILE PHOTO - Signage for Boeing is seen on a trade pavilion at Farnborough International Airshow in Farnborough, Britain, July 17, 2018. REUTERS/Toby Melville

Boeing is the world’s largest planemaker and its commercial backlog is nearly 10 times that of its defence business. The company on Thursday said it won 528 new orders and commitments for commercial aircraft at the Farnborough Airshow this week.

International demand for weapons and defence products and services is also increasing steadily, Gene Cunningham, Boeing’s head of international sales, said in an interview.

Boeing’s Defense, Space & Security business had a backlog of $50 billion with 36 percent destined for non-U.S. customers, the company said on its first quarter earnings call. That compares to $415 billion in commercial backlog.

Over the next 10 years, Cunningham said, “We see the international (sales) number growing to somewhere in the 40 percent range, but we also see the company growing.”

Big wins in the domestic defence sector could alter that forecast, he said.

Boeing is focused on several large competitions in Europe, including Germany’s push to buy around 90 new jets to replace its ageing Tornado fleet.

Germany has said it will prioritise a purchase of more Eurofighter jets, but is also looking at Boeing's F/A-18E/F and F-15 fighter jets, as well as Lockheed Martin Co's LMT.N stealthy F-35 fighter.

Boeing is also eyeing a potential sale of Apache helicopters to Poland as a part of the ongoing KRUK competition that could be decided in 2019. Cunningham said Poland could order about 32 choppers, although numbers have ranged from 16 to 64.

Boeing is also eyeing Switzerland’s competition for a new fighter jet, Cunningham said.

Under its Air2030 programme, Switzerland is seeking to procure new combat aircraft and ground-based air defences in a programme valued at up to 8 billion Swiss francs ($8.08 billion).

Switzerland needs to replace its fleet of Boeing McDonnell Douglas F/A-18C and D Hornets and outdated Northrop NOC.N F-5 Tigers, all of which are scheduled to be retired in the 2020s.

Boeing has annual revenues of about $95 billion dollars.