Irish low-cost airline Ryanair on Tuesday announced that it has ordered 175 Boeing 737-800 airplanes worth $15.6 billion (12.1 billion euros) at catalogue prices. \"Ryanair ... today signed an agreement with the Boeing Company to purchase 175 new Next Generation 737-800 airplanes,\" the Dublin-based carrier said in a statement. The deal was signed by Ryanair chief executive Michael O\'Leary and Boeing Commercial Airplanes boss Ray Conner in New York, where they will hold a joint press conference at 1415 GMT. \"When finalised, the deal will be worth nearly $15.6 billion at current list prices, and will allow Ryanair to grow its airline to more than 400 airplanes, serving more than 100 million passengers per year across Europe by the end of the delivery stream in 2018,\" the statement continued. Ryanair added that it was Boeing\'s largest order to date so far this year, and would support \"thousands\" of jobs in the United States. \"Upon approval by Ryanair\'s shareholders, the purchase will become Boeing\'s largest deal to date in 2013 and will be the largest ever aircraft order from a European airline,\" the Irish company said. \"It will sustain thousands of skilled manufacturing jobs in Boeing and its supplier companies and will represent the largest ever capital investment by an Irish company in US manufacturing and US jobs.\" The news came one day European aviation giant Airbus -- Boeing\'s fierce rival -- announced a record order worth 18.4 billion euros ($23.8 billion) from Indonesia\'s Lion Air for 234 medium-range A320 jets.