The Tokyo and London offices of K&L Gates have advised Japan Airlines (JAL) on a major deal with Airbus, which sees the carrier purchase 31 of the manufacturer's A350 planes.

The agreement, which also includes the option for the delivery of a further 25 aircraft, is JAL's first-ever order with Airbus, and is the largest order for A350 planes in 2013.

In a joint statement, JAL and Airbus said they would hope to see the planes enter into service from 2019, when the airline will begin a six-year programme to replace its ageing fleet.

K&L Gates' Tokyo-based partners Keiji Isaji, Atsushi Yamashita, and Robert Melson led a team advising JAL, alongside London partner Trevor Beadle. They were assisted by counsel Tsuguhito Omagari and associate Nobuhiro Kawanaka, both of the firm's Tokyo office.

Airbus – which takes the place of long-standing JAL supplier Boeing – used in-house counsel for the deal, as it did when Indonesian low-cost carrier Lion Air placed an $24bn (£16bn) order for more than 200 passenger jets earlier this year.

"This is a significant deal for JAL, who up until now almost solely relied on a competing aircraft supplier for its fleet," commented Melson.

"The deal involved lengthy negotiations with Airbus as well as reviewing multiple purchase agreements with both Airbus and engine supplier Rolls Royce. We are delighted that JAL looked to K&L Gates to advise on this major transaction, which marks a new chapter in the airline's fleet planning."

Last week, Legal Week reported that K&L Gates' UK partnership paid out more profit than it earned in 2012, and that it has recently considered leasing out its London offices at One New Change.