Air France says it's canceling 20-30 percent of its flights on Saturday, day two of the European soccer championship, because of a pilots' strike.

CEO Frederic Gagey told reporters on Thursday that the company offered a new proposal in a long-running dispute over working conditions, but unions rejected it.

Pilots unions have called for a strike Saturday to Tuesday, coinciding with the starting matches of the month-long European Championship soccer tournament featuring games in cities around France.

Gagey said the airline would work to limit the impact on traveling soccer fans — but said Air France can only guarantee 70 percent to 80 percent of flights worldwide Saturday.

Strikes in other sectors by unions angry at a labor reform bill may make for a bumpy start to the event.