EXCLUSIVE-Checks seen on some Airbus A380s after 2017 engine explosion

LONDON, Aug 21 (Reuters) - Investigators probing an engine explosion on an Air France A380 in 2017 are studying a possible manufacturing flaw with a key part in a move likely to trigger checks on dozens of Airbus superjumbos worldwide, people familiar with the matter said.

The focus of a two-year-old investigation into the mid-air explosion over Greenland, which left the plane carrying more than 500 passengers with the front of one engine missing, has switched to the recently salvaged "fan hub," the people said.

The titanium part is the centrepiece of a 3-metre-wide fan on engines built for the world's largest airliner by U.S.-based Engine Alliance, co-owned by General Electric and United Technologies unit Pratt & Whitney.

Engine Alliance is expected to order checks for any microscopic flaws on similar parts in its engines, which power some 60 percent of the 237 A380s in service, the people said.

The suspect part was fabricated under the auspices of Pratt & Whitney, which declined to comment.

France's BEA air accident agency, which is leading the investigation, and Airbus both declined to comment. (Reporting by Tim Hepher; Editing by Sudip Kar-Gupta)