WASHINGTON — The Federal Aviation Administration said on Sunday that some Boeing 737 Max planes might have parts that were improperly manufactured, requiring replacements, the latest issue to hit the world’s largest plane maker.

The F.A.A. said up to 148 “leading edge slat tracks” manufactured by a Boeing supplier were affected and cover 179 Max aircraft as well as 133 of Boeing’s 737 NG jets, for Next Generation, the model before the Max. The agency said a complete failure of a leading edge slat track would not bring down an aircraft, but a failed part could damage the plane in flight.

Slats are movable panels that extend along the front of the wing during takeoffs and landings to provide additional lift. The tracks are built into the wing.

The 737 Max was grounded globally in March after a fatal Ethiopian Airlines crash and a crash of a Lion Air jet in Indonesia in October. The two 737 Max crashes killed 346 people.