A fiery object that nearly hit a Sydney-bound airliner over the Pacific may have been a meteorite or debris from a Russian satellite, New Zealand authorities say.

The Lan Chile A340 Airbus was flying between Santiago and Auckland, before heading to Australia, when it came within about 30 seconds of hitting the object about 10pm (2000 AEST) on Tuesday.

The pilots radioed air traffic controllers in New Zealand to report fiery objects falling in front and behind the plane.

Ken Mitchell from Airways New Zealand said the pilot reported the debris was falling "very close" to the plane.

"The pilot estimated the debris to be falling as close as five nautical miles (9.26 kilometres) to the aircraft," Mitchell said.