PARIS, July 27 (Reuters) - French airport operator ADP said it swung to a 543 million-euro ($638 million) first-half net loss as the coronavirus crippled air travel, warning that a return to pre-crisis traffic levels could take as long as seven years.

Revenue for January-June fell 47% to 1.17 billion euros as passenger traffic fell nearly 58%, led by a 62% decline at Paris Charles de Gaulle and Orly airports, ADP said.

"The recovery will be very gradual," Chief Executive Augustin de Romanet said in the company's results statement. "A return to the 2019 traffic level in Paris is anticipated between 2024 and 2027." ($1 = 0.8509 euros) (Reporting by Laurence Frost; Editing by Alison Williams)