(Corrects headline to airports, not airport, paragraph 1 to flights, not flight)

By David Shepardson

WASHINGTON (Reuters) -More than 1,800 flights were delayed and hundreds were canceled at the two Dallas-area airports on Friday, after a telecom outage prompted the Federal Aviation Administration to issue ground stops.

The FAA said it was slowing traffic due to a reported local telephone company equipment issue that does not involve FAA equipment. "The FAA is working with the telephone company to determine the cause," the agency said.

The FAA said it had halted departures to Dallas Fort Worth until 11 p.m. ET and to Dallas Love Field until at least 8:45 p.m. FlightAware said airlines have canceled 20% of their flights at Dallas.

American Airlines canceled more than 200 flights and delayed more than 500, nearly all tied to the Dallas telecom outage -- impacting a quarter of its schedule. Southwest Airlines had delayed more than 1,100 flights, or 27% of its schedule, according to FlightAware, which tracks flights.

The FAA has faced numerous communications issues this year.

On Thursday, the FAA slowed flights into Denver International Airport because automation issues between an approach control tower and Denver air traffic control were requiring manual handoff procedures for flights, causing delays averaging 30 to 45 minutes.

A series of issues involving the aging U.S. air traffic control system prompted Congress in July to award an initial $12.5 billion in funding to overhaul the system, which FAA leaders say is having tech issues almost everyday.

The FAA air traffic control network's woes have been years in the making, but a rush of high-profile mishaps, near-misses, staffing shortages and a catastrophic crash in January between a U.S. Army helicopter and regional American Airlines jet that killed 67 has spiked public alarm.