* Pilots at Stansted had rejected pay deal in October
* Reversal follows Ryanair decision to recognise unions
* Says talks with Dublin holdouts progressing slowly (Adds detail, share price)
DUBLIN, Jan 18 (Reuters) - Ryanair said pilots at each of its 15 UK bases, including its largest company-wide base at London Stansted, accepted pay increases of up to 20 percent that many had rejected last year, sending its shares 3 percent higher on Thursday.
Pilots at Stansted had rejected the offer by a margin of 60 percent to 40 percent in October as Ryanair struggled to contain a revolt that followed its cancellation of 20,000 flights a month over the mishandling of staff holidays.
The reversal follows the Irish airline's shock decision last month to recognise unions for the first time in its 32-year history in order to avoid widespread Christmas strikes.
Ryanair shares were 3.2 percent higher at 16.61 euros by 1400 GMT, returning to the level they were trading at before the announcement on recognising the unions, which had sent the shares down 9 percent in one day in December.
Ryanair, whose outspoken chief executive Michael O'Leary was once quoted as saying he would rather cut off his own hand than recognise unions, has opened recognition talks across Europe and said that discussions with British pilot union BALPA were proceeding quickly.
BALPA said in a statement that it had no part in the pay talks and that "things will be done differently" once they are recognised. Ryanair said it had agreed with BALPA that the pay increases should not be delayed by their negotiations.
Ryanair added that it had asked the one-third of pilots in another of its major European hubs in Dublin that have yet to accept the pay increases to vote on its proposals by Jan. 17 but was disappointed that no such vote was organised.
Talks with the pilots' unions are progressing slowly, it said. (Additional reporting by Alistair Smout in London; editing by Alexander Smith)