(b) The Commissioner shall not grant the request of any group to terminate its certificate of authority unless the group has insured or reinsured all incurred workers' compensation obligations with an authorized insurer under an agreement filed with and approved in writing by the Commissioner. Such obligations shall include both known claims and expenses associated therewith and claims incurred but not reported and expenses associated therewith. Subject to the approval of the Commissioner, a group may merge with another group engaged in the same or similar type of business only if the resulting group assumes in full all obligations of the merging groups. The Commissioner may hold a hearing on the merger and shall do so if any party, including a member of either group, so requests.