Boeing (BA) has secured tentative orders for 30 units of its embattled 737 Max jet from Air Astana.

The Kazakh flag carrier Air Astana said it signed a letter of intent valued at $3.6 billion for the 737 Max jets, which have been grounded globally since March following two fatal crashes.

Earlier Tuesday, the aerospace company also secured firm orders for 20 of the aircraft valued at $2.3 billion from an undisclosed customer, media sources reported, citing a person familiar with the matter.

Shares were marginally lower before midday.