Dummy profit center-company code assignment

Dear Experts,

How to deactivate company code assignment in dummy profit center?

by mistake we selected one company code in dummy profit center, for which profit center accounting is not applicable, so we tried to remove the check box in profit center but in KE52 transaction the company code assignment details are showing in display mode only, please let me know is there any other transaction is there to de activate.

we are using 5.0 version.

so far no posting has been done in this profit center.

Regards

babu