Boeing and BOC Aviation have finalized an order for two additional 737-800s, valued at $186 million at current list prices.

The order is a part of the Singapore-based leasing company’s effort to grow its portfolio of fuel-efficient airplanes.

“Building on our order of 80 737 aircraft earlier this year, these two additional Next-Generation 737s enable us to respond to demand from airline customers which are expanding or replacing older fleets,” Robert Martin, BOC Aviation managing director and chief executive officer, said in a press release. “The 737 is known for its operational and fuel efficiency, and BOC Aviation expects continued healthy demand for the Next Generation 737 and 737 MAX.”

“BOC Aviation has played an important role in the success of the Next-Generation 737 and we are excited to continue our relationship with their order of two additional 737-800s,” said Dinesh Keskar, senior vice president, Asia Pacific and India Sales, Boeing Commercial Airplanes.

BOC Aviation, owned by Bank of China, is the leading global aircraft leasing company based in Asia, owning one of the youngest fleets in the industry with an average aircraft age of less than four years. These two aircraft add to BOC Aviation’s order of 82 Boeing aircraft in August, which comprised 80 737s, of which 50 are 737 MAXs, as well as two 777-300ERs (Extended Range).

The 737-800 is the best-selling version of the highly successful Next-Generation 737 family, the most technologically advanced airplanes in the single-aisle market. The Next-Generation 737 has accumulated more than 6,800 orders from customers worldwide.