The airline, which has its headquarters in Dallas, said it terminated the unidentified flight captain after wrapping up an internal investigation of the July incident that left several passengers with minor injuries, the New York cable channel NY1 reported.
The National Transportation Safety Board said the captain took control from the first officer just a few hundred feet above the ground. The jetliner hit nose-first, collapsing the front landing gear, and slid onto the grass adjacent to the runway.
It was only the second time the pilot, who has 5,200 hours of experience, had landed at LaGuardia and it was his first flight with the co-pilot, who is to undergo further training.
The investigation turned up no mechanical problems with the aircraft.
Flight 345 from Nashville had 150 passengers aboard.