(b) Request for time allotment.

1. (1) If the petition is granted, argument may be made at once or a notice will be served by the commission upon the parties setting the date for the oral argument.
2. (2) At least ten (10) days before any set date, any party desiring to participate in the oral argument must make request by letter (original only need be filed with the commission) for an allotment of time.
3. (3) Only those making request in this manner will be permitted to participate.