If a function or activity previously performed by employees of a participating subdivision is transferred to or otherwise taken over by another participating subdivision and any of the employees performing the function or activity transfer to and become employees of the subdivision taking over the function or activity, with the consent of and on terms approved by the board of trustees, the pension liabilities accrued by the transferring employees for service with the transferring subdivision, together with an appropriate portion of trust assets in the account of the transferring subdivision, may be treated as and considered to be a separate account and pension liabilities of the subdivision taking over the function or activity.