FILE PHOTO: Boeing 737 fuselages sent from Spirit Aerosystems in Wichita, Kansas sit in a BNSF rail siding near Boeing’s Factory in Renton, Washington, U.S. May 16, 2019. REUTERS/Eric Johnson

(Reuters) - Boeing Co’s largest supplier Spirit AeroSystems Holdings Inc is reducing its workweek to 32 hours in response to the 737 MAX groundings, a labor union for the aerospace industry said on Friday.

The changes will be effective June 21 for all salaried, management and executive employees working on commercial airplane programs, the Society of Professional Engineering Employees in Aerospace said.

Spirit said employees have the flexibility to take either Monday or Friday off during the workweek, according to the union.