France and the United States identified the flaperon found on a Reunion Island beach as one from that particular type of Boeing, Malaysia's transportation ministry said. A flaperon is part of an aircraft's wing that helps control its speed and banking angle.
Experts will determine whether the debris found on the French territory of Reunion Island last week is from Malaysia Airlines Flight 370.
The jetliner vanished on March 8, 2014 after leaving Kuala Lumpur, Malaysia, for Beijing. It had 239 people on board.
Work to conclusively identify the piece of wreckage and determine if it is from the missing plane will begin Wednesday, French prosecutors said.
Teams in Reunion are scouring the stretch of coast where the debris was found, and a "metal object of interest" related to the search was discovered Sunday morning on the beach in St. Denis, Reunion Island's capital, a local government official said.
The official declined to be identified because he is not authorized to speak to the media. The official also refused to provide more information, saying the origin of the object needs to be verified.
Malaysian officials said they are reaching out to authorities in territories near Reunion Island to allow experts to conduct more substantive analysis should more debris surface.
In addition to the flaperon and the metal object, other debris washed ashore Thursday that appears to resemble the remnants of a suitcase, local police officials said.
The debris was transferred to Toulouse, France, on Saturday for analysis.
Only 777 aircraft in the Indian Ocean?
Experts from various nations have teamed up to help with the probe in France.
In addition to French officials, experts from Malaysia, China, the U.S. National Transportation Safety Board and Boeing are taking part in the investigation.
And officials are optimistic the latest debris may help resolve the mystery surrounding the jetliner.
"The only 777 aircraft that we're aware of in the Indian Ocean that could have led to this part floating is MH370," said Martin Dolan, the head of the Australian agency coordinating the underwater search for the plane.
"But as I said, we still need to confirm that through closer study."
If confirmed to be part of MH370, the wreckage would be the first bit of physical evidence recovered from that plane.
Dolan said last week that he is "increasingly confident but not yet certain" that the debris is from MH370.
The French General Directorate of Armament, which is analyzing the debris, has sophisticated equipment and expertise to quickly identify the plane the debris belongs to and what happened to it.
That analysis will begin Wednesday, the Paris prosecutor's office said.
Authorities have so far been unable to establish why Flight 370 flew sharply off its route from Kuala Lumpur and disappeared.
A preliminary assessment by U.S. intelligence agencies
suggested someone in the cockpit deliberately caused the aircraft's movements before it vanished.