Thai Airways International PCL (THAI.TH) said its board has approved the procurement of 37 aircraft between 2011 and 2017 for THB118.60 billion ($3.89 billion), including the purchase of six planes from Boeing Co. (BA) and five from Airbus.

The national carrier will use working capital to fund the aircraft procurement, it said in a filing to the Stock Exchange of Thailand.

Under the plan, Thai Airways will purchase six Boeing B777-300ER aircraft, with delivery in 2014 and 2015; four Airbus A350-900's for delivery in 2016 and 2017; and five Airbus A320-200's for delivery in 2014 and 2015.

It will also obtain 22 aircraft under an operating lease.

-By Bangkok bureau, Dow Jones Newswires; 66 2690 4200; djnews.bangkok@dowjones.com