AirAsia X says new offshore joint ventures will play a major role in utilizing the 31 additional Airbus A330-300s that the long-haul, low-cost carrier plans to add to its fleet through a new order and a lease deal.

The Malaysia-based airline has announced an order for 25 A330s for delivery from 2015, to be supplemented by another six A330s to be leased from International Lease Finance Corporation. The airline, which is an affiliate of the AirAsia group but is listed independently, already operates a fleet of 16 A330-300s. The latest agreement with Airbus will take its firm orders for the type to 51, and the airline also has 10 A350s on order.

AirAsia X says the new order includes the extended range version of the A330-300, which provides it with “the ability to offer non-stop service to destinations in Europe or one-stop service to the U.S.” AirAsia X has previously operated flights to London and Paris using A340-300s, but cut these routes in March 2012.

Airbus announced the extended-range option for the A330s in November 2012, and it will be available to operators from 2015. This boosts the maximum takeoff weight capability, and for the -300, adds fuel capacity to increase its range by 500 nm.

The order signals a new wave of growth for AirAsia X. AirAsia Group CEO Tony Fernandes says the additional aircraft “further cater to our expansion plans in Malaysia,” as well as “other long-haul ventures planned across Asia.” This will “strengthen the connectivity between [the group’s] long-haul and short-haul” operations.

AirAsia X CEO Azran Osman-Rani has previously said that the carrier’s goal is to launch overseas joint ventures in cities where AirAsia has already established short-haul affiliates. This will ensure the long-haul operation has a feeder network. The first two offshore ventures for AirAsia X will be based in Thailand and Indonesia, although Osman-Rani has said that it could be years before any other AirAsia short-haul hub –beyond these two – is mature enough to have its own long-haul affiliate based there.

The Thailand AirAsia X joint venture is furthest advanced, and is expected to be operational in early 2014. AirAsia already has a well-established short-haul joint venture in this market, which is seeing a surge in LCC activity.

Thailand-based LCC Nok Air this week announced it will form a long-haul joint venture in partnership with Scoot, a Singapore Airlines subsidiary that is also based on the long-haul low-cost model.