In:
No. Work Permit or S Pass holders are not allowed to carry on or manage any business in Singapore. As such, they cannot register themselves as sole-proprietors, partners or directors of any Singapore-registered company.
By doing so, they will have infringed the work pass conditions and their work passes will be revoked. They will also need to serve an employment ban.
Concluded answer: Work Permit and S Pass holders are not allowed to administer or manage any business in Singapore. Please refer to the above image of screenshot from MOM.