40 Pa. Stat. § 440.1
Two or more insurance companies, associations or exchanges, authorized to transact the same kinds of insurance business in this Commonwealth, may issue a combination policy, using a distinctive title therefor, which title shall follow the titles of the several companies, associations or exchanges obligated thereby. Such policy shall be executed by each such company, association or exchange, in the same manner as it would execute its individual policy. Such policy shall state that it is a joint contract and that each company, association or exchange is only liable for a specific percentage of any loss or damage occurring thereunder. Before any such companies, associations or exchanges shall issue such combination policy, they shall receive the express permission of the Insurance Commissioner to issue the same and the title shall be approved by him.
40 P.S. § 440.1