Ryanair said today it had reached a deal with Portuguese pilots on seniority and home base issues, following similar agreements with their counterparts in Britain and Italy this week.
The airline also expects to sign a recognition agreement with the union representing Spanish pilots shortly as it seeks to end a damaging series of strikes that have hurt its business.
Ryanair has struggled with labour relations since it bowed to pressure to recognise unions for the first time almost a year ago.
It said the Portuguese deal - covering issues such as leave allocation and promotion - would allow talks with Portugal's SPAC union on a full collective labour agreement to start by the end of the month.
A recognition agreement in Spain will also pave the way for rapid negotiations on a full labour agreement with Spanish pilot union SEPLA, Ryanair added.
Ryanair signed its first recognition agreement with pilots in its largest market of Britain earlier this year where it has avoided industrial action. Pilots in Italy approved a collective labour agreement in August.
"These signed agreements with our pilot unions in Portugal, the UK, Italy and shortly in Spain, demonstrate the considerable progress we're making in concluding union agreements with our people in our major EU markets," Ryanair's chief people officer Eddie Wilson said in a statement.
"I expect that these agreements in Spain, and Portugal in particular, will encourage the cabin crew unions in both those countries... to quickly conclude cabin crew agreements."
Cabin crew in Spain and Portugal took part in a walkout across six European countries last month that disrupted the plans of more than 40,000 passengers in one of Ryanair's worse strikes to date.
Meanwhile, two Belgian unions representing Ryanair cabin crew warned of several more days of strikes in Europe before the end of the year if Ryanair does not change its position in negotiations.