Ryanair, Europe's largest low-cost airline, posted an above-forecast 21-percent rise in first-quarter earnings on Tuesday but stuck with its prediction of a winter fares war which would cause an industry shake-out. The Irish-based carrier, which has been slashing ticket prices to fill seats amid cut-throat competition, reported adjusted earnings per share (EPS) of 7.0 euro cents in the three months to end-June. The average EPS forecast in a Reuters survey of Dublin-based analysts was 6.65 cents.