UPDATE 1-Mexico airport operator Asur's net drops 27 pct

(adds detail, stock price)

MEXICO CITY, Oct 22 (Reuters) - Mexican airport operator Grupo Aeroportuario del Sureste posted a 27 percent year-on- year drop in net profit in the third quarter, as the H1N1 flu outbreak and economic slump led fewer people to travel.

The company, known as Asur (ASURB.MX)(ASR.N), earned 171 million pesos ($12 million) between July and September, compared with 234 million pesos in the same quarter of 2008.

Passenger traffic was down 14 percent in the quarter and revenues fell almost 3 percent to 715 million pesos, Asur said in a statement on Thursday.

Traffic at Asur's busy Cancun, Cozumel and Oaxaca airports, all popular tourist destinations, dropped sharply in the quarter, compared with the year-earlier period.

Mexico was the epicenter of an outbreak of a new flu virus in April, which greatly hurt the country's tourism and airline industries. Foreign visitors remain cautious about traveling to Mexico although the disease has spread globally.

Asur shares fell 2.76 percent to 59.17 pesos in morning trade on Thursday. ($1 = 13.5035 pesos at end September) (Reporting by Noel Randewich and Cyntia Barrera Diaz)