* Airlines unsure when commercial service will resume
* UPS, FedEx holding deliveries
* Firms launch aid efforts
* Royal Caribbean says Labadee appears undamaged
* US FAA sends experts to assess airport damage (recasts, adds AMR relief efforts, Dominican tourism)
NEW YORK/WASHINGTON, Jan 13 (Reuters) - U.S. airlines and package companies suspended commercial flights to quake-ravaged Haiti on Wednesday and launched relief efforts along with aviation authorities who sought to revive airport operations.
American Airlines, a unit of AMR Corp AMR.N, flew its last commercial flight from Haiti to Miami on Tuesday night just after the earthquake struck.
Many of the passengers aboard Flight 1908 opted off the aircraft amid the quake’s aftermath, an airline spokeswoman said. The plane took off with 49 passengers only after the runway was checked for damage.
American scheduled three relief flights on Wednesday to the capital, Port-au-Prince. Each carried 10,000 pounds of supplies for the airline’s 100 employees in Haiti as well as materials for local hospitals. American has scheduled another three relief flights for Thursday, the company said.
Other commercial carriers, including Continental Airlines CAL.N, said they were ready to help, if necessary. Continental doesn't fly into Haiti.
In many cases, commercial airlines hold contracts with the U.S. government to ship personnel and materiel for the military or humanitarian supplies in disasters.
American, and private Spirit Airlines which also canceled it flights, set aside frequent flier miles in exchange for Haiti relief donations.
Both companies also said they are working with international relief agencies to help transport supplies into the disaster zone.
Airports in Port-au-Prince and Cape Haitien were open to a limited number of rescue and relief flights only, U.S. aviation officials said.
Haiti has little modern infrastructure and the quake knocked out air traffic control capabilities at both airports. Flights only operated if the weather remained clear. Military officials oversaw operations.
The U.S. Federal Aviation Administration (FAA) said it sent experts to Toussaint Louverture International Airport in Port-au-Prince. They will inspect navigation systems and oversee needed repairs to ensure more relief flights and to restore commercial service.
“They’ll look at runway lights and the ability to accommodate planes on the ramp and all the things you need for fueling to support planes arriving and departing,” FAA spokeswoman Laura Brown said.
The U.S. State Department urged Americans not to travel to Haiti.
American and Delta Air Lines Inc DAL.N canceled their flights to Haiti but were operating to the Dominican Republic, which shares the eastern third of the Island of Hispaniola with Haiti.
Royal Caribbean Cruises Ltd RCL.N said its private beach destination in Labadee, Haiti, reported no apparent damage to the company's buildings, pier and attractions. It added that all of its workers in Labadee were accounted for and had no injuries.
Royal Caribbean’s Independence of the Seas cruise ship is scheduled to go to Haiti on Friday. Three other ships are slated to stop in Haiti next week.
The Dominican Republic said in a statement it was staging sites for relief efforts at local airports and providing medical and other relief to Haiti.
The Dominican government said there was no damage to its transportation or communications systems. Its medical facilities and tourism sites also were unaffected by the quake. For details on the earthquake, please see ID:nN13137542
For a map of Haiti locating the epicenter of the earthquake, see here. (Reporting by Deepa Seetharaman in New York, Scott Malone in Boston, John Crawley in Washington Kyle Peterson in Chicago and Karen Jacobs in Atlanta. Editing by Gerald E. McCormick, Robert MacMillan and Carol Bishopric)