SILKAIR will have a new chief executive from September 3, when current Singapore Airlines (SIA) vice president Network Planning, Leslie Thng, replaces incumbent Marvin Tan.

Thng, who has been with the Singapore flag carrier for the past 13 years, joined its regional wing SilkAir as a board director on April 1, 2012.

Before taking on his current role, Thng was based in Frankfurt as SIA's general manager for Germany. Prior to that, he was based in Italy and China for more than four-and-a half-years. He also previously worked in the airline's Loyalty Marketing and Network Revenue Management departments.

Tan, who has been CEO of SilkAir since October 2010, will be returning to SIA as senior vice president Cabin Crew.

Meanwhile, SilkAir has signed a letter of intent to buy 23 Boeing 737-800 and 31 Boeing 737 MAX 8 aircraft, with purchase rights for another 14 planes. The US$4.9 billion combined list price for the firm-ordered aircraft is the largest in SilkAir’s history.

Deliveries are scheduled to begin in 2014 and continue till 2021, by which time SilkAir's fleet would have more than doubled in size. The carrier currently operates 21 Airbus A319s and A320s, with three more A320s due for delivery by end-2013.