European budget airline Ryanair posted its first fall in full-year net profit in five years, as the company tackled a tough environment and new larger planes giving it more seats to sell in the coming year.

Profits fell 8 percent to 523 million euros ($717 million) from 569 million euros, according to the Irish company's statement on Monday, with CEO Michael O'Leary calling it "disappointing". His colleague Howard Millar, the chief financial officer at Ryanair, told CNBC that warm weather last summer meant many holiday makers stayed at home and a weak sterling currency also weighed on profits.