The 777-300ER that will be leased over the 7 to 23/December period has the register number EC-MIA and was previously operated by Asiana Airlines.
Finnair had previously stated that it would receive 4 A350-900s this year and announced that they were going to be the first airline to fly to New York with the A350 XWB.
But the Finnish flag carrier has recently changed its phrasing, stating only that it will have 5 of the type by the end of the first quarter of 2016.
Finnair said the delivery of the A350 requires "airline-specific preparations and comprehensive inspections" and had warned of possible slight changes to delivery dates.
Based on the article "Finnair leases 777 to cover for A350" published in FlightGlobal.