(Adds Moody's warning, background)
By Anthony Esposito and Felipe Iturrieta
SANTIAGO, Feb 8 (Reuters) - Concerns over the Zika virus have not affected ticket sales at LATAM Airlines' TAM Brazilian unit, the regional carrier said on Monday.
"So far, there has been no impact on reservations at TAM ... due to the cases of Zika virus in Brazil and in other locations where the airline operates," Chile-headquartered LATAM said.
The rapidly spreading Zika virus, suspected to be linked to thousands of birth defects in Brazil, appears to be discouraging some tourists from traveling to Latin America and the Caribbean.
A Reuters/Ipsos poll showed on Sunday that about 41 percent of U.S. respondents who were aware of the disease said they were less likely to take such a trip.
Ratings firm Moody's warned on Thursday that TAM and smaller Brazilian carrier Gol Linhas Aereas SA were the most exposed to an expected reduction in air travel to Latin America due to Zika.
LATAM Airlines is offering refunds or the option of itinerary changes to pregnant women planning to travel to Latin American and Caribbean countries affected by Zika.
Much remains unknown about Zika. Brazil is investigating the potential link between those infections and more than 4,000 suspected cases of the microcephaly birth defect, which is marked by an abnormally small head size that can result in developmental problems.
Researchers have identified evidence of Zika in 17 of these cases, either in the baby or in the mother, but have not confirmed that the infection can cause microcephaly.
The World Health Organization declared the outbreak an international health emergency on Feb. 1, citing a "strongly suspected" relationship of Zika infection in pregnancy to microcephaly.
Reporting by Anthony Esposito and Felipe Iturrieta; Editing by Chizu Nomiyama and Lisa Von Ahn