Malaysia Airlines (MAS) has ordered 20 additional ATR aircraft for its regional subsidiaries, with options for 16 more.

Of the 36 orders and options, MAS turboprop operations Firefly and MASwings will be allocated 20 and 16 aircraft respectively, Firefly CEO Ignatius Ong tells Aviation Week. He says first deliveries will be in the second quarter of 2013. All the new aircraft are understood to be ATR 72-600s, ATR’s newest model.

Firefly currently operates 12 ATR 72-500s, and MASwings operates 10. Neither had any ATRs left on order, but Ong told Aviation Week earlier this year that Firefly and MASwings planned to order ATR 72-600s. ATR is ending production of the -500 model.

Firefly is based in west Malaysia, while MASwings is based in East Malaysia. It is understood that Firefly has been considering the merits of establishing an offshoot in Indonesia. Ong, however, declines to confirm this. “We keep all options open, but none is planned as of now,” he says.

In a separate development, ATR is competing against Bombardier to secure an order from Garuda Indonesia’s Citilink.

Industry sources say Citilink is due to make a decision as early as Dec. 18 and no later than Dec. 21. Garuda has said the order will be for 50 aircraft, but this number includes options. Industry sources say the initial deal will be 25 firm orders and 25 options.