The order stems from options contained in a previous purchase contract. Deliveries for this order begin in 2008. The order was previously accounted for on Boeing's Orders and Deliveries website and attributed to an unidentified customer.
The airplanes will be fitted with blended winglets, which are said to reduce drag and improve fuel efficiency by three to five percent.
Ryanair recently completed its Boeing 737-200 replacement program, and today operates one of the youngest aircraft fleets in Europe, composed entirely of 737-800s.
"We are delighted to be buying a further 10 Boeing 737-800s that will allow us to bring even more low fares with a no-fuel-surcharge guarantee to the people of Europe," commented Michael O'Leary, CEO of Ryanair.
As of May 31, 2006, 97 customers had placed orders for more than 3,200 Next-Generation 737s. The program has more than 1,200 units of unfilled orders with a value of around $85 billion at current list prices.