prohibited transaction issue - referral/finder's fee issue

[EGB]

Can anyone point to some authority on the following issue (note: I am already aware of DOL Adv. Ops. 82-55A and 82-65A):

Bank trust department wants to pay referral/finder's fees to employees of its affiliate banks who refer qualifed plan trust business to said trust department. Such fee would be an ongoing annual fee as long as the trust business remains with the Trust Dept. and would be based on a percentage of the trustee's fees(which trustee fees would be equal to any 12b-1 fees received from the mutual funds, assuming that such trustee's fees are reasonable in amount).

Ex: Employee A of Bank A tells Company X to call Trust Dept. (an affiliate of Bank A) regarding acting as trustee of Company X's 401(k) plan. Company X makes the call and Trust Dept. becomes trustee of Company X's 401(k) plan. Accordingly, Trust Dept. pays Employee A a referral/finder's fee for so long as Trust Dept. continues to act as trustee of Company X's plan. The referral fee would be based on a percentage of the trustee fees. The trustee fees are equal to any 12b-1 fees/sub-trasfer fees/finder's fees the Trust Dept. receives from mutual funds in connection with the investment of the 401(k)'s assets in said mutual funds.

Prohibited Transaction?