Federal aviation regulators criticized commercial-jet makers Thursday for resisting "any concerted effort" to upgrade onboard flight-data and cockpit-voice recorders on the latest models coming off assembly lines.

The Federal Aviation Administration said it was "seriously disappointed" with what it contends has been 19 months of industry foot-dragging in implementing the safety enhancements. On Thursday, the FAA announced it was reluctantly proposing to extend the timetable for installing enhanced recorder equipment on newly...