Boeing [NYSE: BA] and Virgin Australia today finalized a firm order for 23 fuel-efficient 737 MAX airplanes with options for four additional 737 MAX airplanes.

With this order, Virgin Australia becomes the first Australian airline to finalize an order for the new 737 MAX, while adding to their existing fleet of 68 Next-Generation 737 airplanes.

“Boeing shares a longstanding relationship with Virgin Australia and we are honored to partner with Virgin once again as the country’s first customer for the new 737 MAX,” said Brad McMullen, Vice President of Japan & Oceania Sales, Boeing Commercial Airplanes. “The 737 MAX will provide passengers with unrivaled comfort as well as tremendous economics and reliability to Virgin Australia’s growing operations,” McMullen said.

The 737 MAX will deliver the big savings in fuel that airlines want. Powered by the CFM International LEAP-1B engines, it reduces fuel use by an additional 13 percent over today’s most fuel-efficient single-aisle airplanes. The 737 MAX’s more efficient structural design, less engine thrust and less required maintenance also add up to substantial cost advantages for customers. The 737 MAX 8 will have the lowest operating costs in the single-aisle segment, with an eight percent per-seat advantage over its competitor.

Virgin Australia established its operations in Australia with two Boeing 737 airplanes in August 2000. The airline operates a mix of 73 narrow and wide body Boeing airplanes.

Ailerons for all Boeing 737 airplanes are manufactured in Australia by Boeing Aerostructures Australia.