SEATTLE, Dec. 13 /PRNewswire-FirstCall/ -- Boeing (NYSE: BA) and GE Commercial Aviation Services (GECAS) today announced a 55-airplane order that includes 53 Next-Generation 737-800s and two Boeing 777-300ER (Extended Range) passenger jetliners. The order, valued at approximately $4.5 billion at list prices, includes an exercise of existing options and was listed last week on the Boeing Orders & Deliveries Web site, attributed to an unidentified customer. "This additional order with Boeing will allow GECAS to help our customers around the world benefit from the leading-edge operational efficiency and excellence that the Boeing Next-Generation 737 and 777-300ER aircraft deliver," said Henry Hubschman, president and CEO of GECAS. "Today's order by GECAS reaffirms the Boeing Next-Generation 737 as a highly successful asset, both in operation with our airline customers and in the financial community. GECAS, already the world's largest owner of 737s, continues to add to its portfolio with 309 total Next-Generation 737 orders," said Scott Carson, president and chief executive officer of Boeing Commercial Airplanes. "GECAS has also been a leader in contributing to the success of the market-leading Boeing 777, which has accumulated 129 orders this year alone, and more than 1,000 orders from 53 different customers since its launch." The Next-Generation 737 family is the most technologically advanced airplane family in the single-aisle market. The Next-Generation 737's market success is confirmed by air finance investors, who consistently rank it as the most preferred airplane due to its wide market base, superior efficiency and lowest operating costs in its class. To date, 109 customers have placed orders for more than 4,300 Next-Generation 737s. Unfilled orders for the Next-Generation 737 exceed 1,800 airplanes, worth over $130 billion at list prices. The fuel-efficient 777-300ER is the world's largest long-range twin-engine jetliner and is capable of carrying 365 passengers up to 7,930 nautical miles (14,685 kilometers). The General Electric GE90-115B, the world's largest and most powerful jet engine, powers the 777-300ER. GECAS has previously ordered 39 777s, and to date has taken delivery of 18. Boeing has more than 350 unfilled 777 orders, worth about $90 billion at list prices. GE Commercial Aviation Services (GECAS), the U.S. and Irish commercial aircraft financing and leasing businesses of GE, has a fleet of 1,450 owned aircraft it leases to more than 230 airlines in some 70 countries, and it manages nearly 300 aircraft for others. GECAS offers a wide range of aircraft types and financing options, including operating leases and secured debt financing, and also offers productivity solutions including spare engine leasing and spare parts financing and management. GECAS, a unit of GE Infrastructure, has offices in 28 cities around the world.