April 16 (Reuters) - Air France said on Monday it had proposed a final pay offer to unions in a bid to end costly strikes.
The airline said it was offering an additional pay increase of 1 percent for 2018, taking the overall increase to 2 percent.
For 2019, 2020 and 2021 Air France said it was offering a general wage increase of 5 percent, equivalent to 1.65 percent per year.
The airline said the estimated cost of the strikes, including action planned for April 17 and 18, was 220 million euros ($272 million).
The pay offer is open up until April 20 at midday local time (1000 GMT), Air France added. ($1 = 0.8079 euros) (Reporting by Alan Charlish Editing by Alexander Smith)