Airlines slashed more than half of their usual flight schedules at Paris's main airports, Orly and Roissy Charles-de-Gaulle, with significant grounding of flights also observed in Marseille.
Short and medium-haul flights bore the brunt of the disruptions, while long-haul services experienced comparatively less impact.
French civil aviation authority DGAC forecasted approximately 2,600 flights at French airports on Thursday, down from 5,200 the day before. Across Europe, about 2,000 additional flights were canceled, with another 1,000 forced to alter routes to avoid French airspace, as reported by the Airlines for Europe trade body.
Augustin de Romanet, CEO of ADP, the company managing Paris's airports, noted that cancellation figures were the highest seen in 20 years.
Air traffic controllers' demands for a 25 percent pay rise over five years and accusations of "blackmail" from industry associations added tension to the situation.
While delays for operational flights were relatively moderate, French holidaymakers, many of whom were on spring break, faced significant challenges. Airlines offered options for passengers to change reservations or obtain refunds.
Ryanair reported 300 cancellations, while EasyJet and Transavia each canceled 200 flights. Ryanair CEO Michael O'Leary criticized the disproportionate impact on overflights due to French strikes, urging EU Commission intervention.
The strike stemmed from concerns over a planned overhaul of French air traffic control systems, raising fears of further disruptions during the upcoming Olympic Games in Paris.