Two or more employing units that have made an election may submit a joint application to the Secretary for establishment of a group account to share the cost of benefits that are attributable to covered employment for those employing units. The application shall identify and authorize a group representative to act as the agent of the group. On receipt of an application, the Secretary shall approve or disapprove the application. On approval of an application, the Secretary shall: establish a group account for the group, effective on the first day of the calendar quarter in which the Secretary receives the application; and notify the group representative of the effective date of the account. A group account shall continue to be effective: for at least 1 year; and until terminated at the discretion of the Secretary or on application by the group. On receipt of a bill that the Secretary sends to the group, each member of the group is liable for reimbursement payments in an amount whose ratio to total benefits that are attributable to covered employment for all members of the group is the same as the ratio that as total wages paid by that member has to total wages paid by all members of the group. The Secretary may adopt regulations for: application for the establishment, maintenance, and termination of a group account; addition of new members to a group account; withdrawal of active members from a group account; determination of the amounts that are payable under this section by each member of a group; and manner and time of payments by a member of a group.