Okay to grant service with previous employer?

[John A]

Can the plan sponsor of a 401(k) plan grant service credit to new employees for their service with their previous employer, on a new hire by new hire basis, even if the previous employers were not related to the employer sponsoring the plan, provided it is done in a manner that does not discriminate in favor of HCEs? If this cannot be done, please provide a cite showing that this cannot be done.

Thank you!