"The options and various arrangements including the recent MoU with Boeing, will allow us to have some flexibility in deciding, which aircraft suits our operational environment best", it said.
The funding for the 25 aircraft is planned on a sale-and-operating leaseback or simple operational lease, the national carrier said yesterday.
The 48 existing planes are part of its current 54-aircraft fleet of 737-800; the balance six will be handed back to lessors in December this year.
Malaysia Airlines said it would continue to carefully evaluate all options available to ensure its purchases make both business and operational sense.
"This is necessary and in line with ongoing prudent fleet management and cost containment efforts across the group", it noted.
Japan Airlines has announced an order today for four 787-8 Dreamliners from Boeing.
Malaysia Airlines said the eight Boeing 787-9 Dreamliner aircraft have a list price of US$2.5 billion (RM10.50 billion) and it would negotiate extensively to ensure the best value on confirmation of order.
Flight Fleets Analyzer shows that JAL already operates a fleet of 25 787-8s and nine -9s, while it has 11 more of the latter on order. The transaction, previously attributed to an unidentified customer, will expand JAL's Dreamliner fleet to 49 aircraft.
With this new order, Japan Airlines' 787 fleet include 29 787-8s and 20 787-9 airplanes.
In the mean time, the airline said it is also considering to go with either used Airbus A330-200/300 or new Airbus A330neo aircraft for its expansion and replacement of existing aircraft.