Emergency officials in Steuben County say six tank cars carrying propane left the tracks around 6:30 p.m. Wednesday at the Dresser Rand plant in the village of Painted Post, just north of Corning.
Authorities say none of the cars overturned and none of the fuel leaked.
Traffic had to be detoured around the accident while emergency crews remained at the site.
There was no immediate information on what caused the derailment.
No injuries were reported.