Some 15 million visitors are predicted to attend the Games, including two million from abroad, according to the Centre for Law and Economy of Sport (CDES), which has been monitoring the Paris Games for the IOC and the Paris 2024 organisers.
But there have been concerns that the Games may keep other travellers from visiting Paris, which is a major tourist destination during the summer.
"International markets show a significant avoidance of Paris," the airline said in a statement.
"Travel between the city and other destinations is also below the usual June-August average as residents in France seem to be postponing their holidays until after the Olympic Games or considering alternative travel plans," it added.
Air France-KLM said it has no plan to scale back capacity, despite the estimates of negative impact on its revenues for the June until August 2024 period.
It said it would provide more details when presenting half year results on July 25th.
"Travel to and from France is expected to normalise after the Olympic Games, with encouraging demand levels projected for the end of August and the month of September," it added.
Official partner
Air France-KLM shares were up 0.6 percent in morning trading -- far below the blue-chip Paris stock exchanges' CAC 40 index which was up more than two percent, on relief the far right did not win an outright parliamentary majority in the first round of parliamentary elections over the weekend.
The airline's shares are trading around a 10-year low.
As late as April Air France-KLM was talking about promising ticket sales levels for the summer and said it aimed to boost its seat capacity by five percent from the previous summer.
One of the official partners of the Paris Olympic and Paralympic Games, Air France had said plans to use the events to boost its brand and show off its services. It has hired hundreds of temporary staff to help ensure smooth travel for athletes and their equipment.
The airline expects to transport around a fifth of the Olympic athletes and just over a third of the Paralympic athletes.
At the beginning of June, the airline's chief Anne Rigail said it would hit this summer the level of its pre-pandemic activity for the first time.
The June-August quarter is a crucial period financially for airlines in the northern hemisphere as summer vacation season helps them generate much if not most of their profits.
Last year, Airbus-KLM posted a net profit of 931 million euros in the third quarter, nearly the exact amount of its record annual earnings.
Monday's warning came as AirFrance-KLM has struggled this year, losing 522 million euros in the first quarter on rising costs and geopolitical tensions despite a higher number of passengers and higher ticket prices.
The group has launched a cost-cutting plan including a hiring freeze for administrative and non-operational staff.
