TUI AG and Thomas Cook Group Plc, Europe’s two largest tour operators, canceled all U.K. flights to Cancun following Mexico’s swine flu outbreak.

TUI said customers of its Thomson and First Choice units will return from Mexico on their scheduled flights and the company won’t send any more vacationers to the country until May 8. Earlier today, TUI said it would repatriate customers and wouldn’t resume flights to Mexico until the Foreign and Commonwealth Office changed its advice that Britons should avoid all but essential travel to Mexico.

Arcandor AG’s Thomas Cook unit canceled flights for the next seven days and like Sol Melia SA is allowing customers booked on trips to the country to switch to an alternative destination.

More than 150 people have died of flu-related causes in Mexico, and the World Health Organization raised its global pandemic alert yesterday, saying the disease is no longer containable. Mexico got $13.3 billion of tourism revenue last year, making it the country’s third-largest source of foreign currency behind oil exports and migrant worker remittances.

Mexico accounts for 2 percent to 3 percent of TUI’s tourism revenue, TUI U.K. said in the statement this morning.

TUI fell 4.2 percent in Frankfurt trading today, while TUI Travel Plc slid 3.6 percent in London. TUI owns 51 percent of the U.K.-listed unit.

Condor Flights

Thomas Cook dropped 1.7 percent in London, while Sol Melia declined 5.2 percent in Madrid trading.

Passengers booked to fly to Mexico on Thomas Cook’s Condor airline will be allowed to pick another destination until May 4, spokeswoman Nina Kreke said today. Condor doesn’t plan on canceling its three flights a week from Frankfurt to Cancun.

Sol Melia, the world’s largest resort operator, is offering guests booked for its nine hotels in Mexico alternatives in the Caribbean, such as Puerto Rico and the Dominican Republic.

Sol Melia Chief Executive Officer Gabriel Escarrer Jaume said yesterday that the effect is more limited at this time of year than it would be in the peak season around December.

Palma de Majorca, Spain-based Sol Melia has about 4.5 percent of its 76,900 hotel rooms in Mexico. The company said May and June revenue from that market is about 1 percent of the company’s annual sales.

The World Tourism Organization, a Madrid-based United Nations agency, said it’s not recommending any travel or trade restrictions. Last month, the World Tourism & Travel Council estimated global travel revenue will fall 3.6 percent this year.