Ryanair has recognised the British Airline Pilots' Association, the trade union said, as it moves to recognise pilot associations in Europe for the first time.
BALPA said the move followed Ryanair's announcement before Christmas that it was changing its stance towards unions and was willing to enter into discussions about recognising pilots' unions in a number of European countries, including the UK.
"Given Ryanair's previous hostility towards unions, today's agreement is an historic one," said Brian Strutton, General Secretary of BALPA.
"While we were initially sceptical about Ryanair's sincerity in offering recognition to us and other unions, our conversations and meetings with them have shown that they are genuine in wanting a constructive trade union relationship."
Under the agreement, BALPA will be recognised as the sole trade union representing all of Ryanair's 600 employed pilots based in the UK.
In a statement, Ryanair said it welcomed the "positive and constructive" engagement of BALPA and looks forward to working with the union.
The airline said the move is significant because the UK accounts for almost 100 of Ryanair’s 400 plus current aircraft fleet and over 25% of Ryanair’s pilot body.
Ryanair Chief People Officer Eddie Wilson said: "This agreement validates the decision of Ryanair's board in December to recognise unions, and the fact that we have delivered pay rises of up to 20% and union recognition for our pilots in our largest market, shows how serious Ryanair is about working constructively with unions that are willing to work constructively with us."
The airline said the UK deal is in "marked contrast" to some other EU countries where it says Ryanair is still waiting for a response to recognition proposals.
Ryanair's statement called on unions to "stop wasting time and act quickly" to conclude formal recognition agreements, which they are "presently sitting on".
It said it has warned the FORSA union and the Irish Airline Pilots' Association that the company will offer pay rises to pilots individually if they refuse or fail to organise a vote on the issue before a deadline set tomorrow.
The IAPA said it is due to meet today to discuss union recognition with Ryanair, but it could not say if any agreement will be reached by Ryanair's deadline.
