Nepal Airlines is searching for a supplier to provide short-take-off aircraft, and has issued a formal request for proposals.
The carrier is seeking three newly-built STOL aircraft with at least 18 seats.
It states that they should be reconfigurable, such that the seats can be removed or folded in order to transport cargo.
The aircraft must be able to operate from a 1,500ft runway and have payload-range capability to transport 1.8t of cargo over 100nm.
Nepal Airlines intends to take delivery of the first airframe six months after agreeing a contract, and the other two at six-month intervals.
Bidders must submit their proposals by 5 December.
Nepal Airlines operates a fleet including Airbus A330 and A320 jets, but also Viking Air DHC-6-300 Twin Otter turboprops.