An airport ramp crew found the loaded .38 caliber handgun after it fell out of an unzipped compartment of a duffel bag they were loading onto Alaska Airlines Flight 563, the Times reported.
The ramp workers alerted LAX police to report their find.
Police questioned the gun's owner, later releasing him and allowing him to board a later flight to Portland. He turned the gun over to the LAPD, the Times reported.
The Times attributed the information to several 'unnamed law enforcement sources.'
A TSA spokeswoman said she was unfamiliar with the incident.
The traveler did not give Alaska Airlines the required notification that he planned to travel with the gun in his bag, the Times reported.
He told authorities that he flew out of Portland using the same bag -- with the gun inside -- three days prior.