Section 102A. Two or more stock or two or more mutual fire companies may issue a single policy of insurance against loss or damage by fire, or by fire and lightning, on property or interests in the commonwealth on which each company shall be severally liable for a specified percentage of any loss or claim. Such policy may also include insurance against loss or damage to any property of the insured and against legal liability for loss or damage on account of the bodily injury or death of any person or any damage to property of another caused by the hazards specified in the fifth clause of section forty-seven. Such policy shall be executed by the duly authorized officers of each company, subject to the provisions of section thirty-three in the case of a domestic company.

No such policy shall be issued or delivered until a copy of the form thereof has been on file for thirty days with the commissioner, unless before the expiration of said thirty days he shall have approved the form of the policy in writing; nor if the commissioner notifies the company in writing within said thirty days that in his opinion the form of the policy does not comply with the laws of the commonwealth, specifying his reasons therefor; provided, that such action of the commissioner shall be subject to review by the supreme judicial court; nor unless it is headed by the corporate name of each company; nor unless it contains in substance the provisions of the seventh and eighth clauses of section ninety-nine and is, except as hereinafter provided, in the standard form prescribed by said section; provided, that said provisions and said standard form may be modified as to form and arrangement but only in such manner as the commissioner may prescribe; nor unless it contains in substance:—

(1) A provision plainly specifying the percentage of any loss or claim for which each such company shall be liable.

(2) A provision that the sworn statement required by said standard form, the written request by the insured for a reference under section one hundred or the notice of any claim authorized by section one hundred and two may be rendered, made or given to any one of such companies or, in the case of said notice, to the agent of any one of such companies, and that such statement, request or notice so rendered, made or given shall be valid and binding as to all of such companies.

(3) A provision that, in any action or suit under the policy, service of process may be made on any one of such companies and that such service shall be deemed valid and binding service upon all of such companies.

(4) A provision, in the case of a policy issued by mutual companies, that the contingent mutual liability of the insured to each such company shall be based on such proportion of the total premium as the amount insured by each such company bears to the total amount insured under the policy.

(5) A provision that upon cancellation by any company of its liability under the policy the return premium, if any, to be paid or tendered to the insured shall be based on such proportion of the total premium stated in the policy as the amount insured by the cancelling company bears to the total amount insured under the policy.

The said provisions shall be printed in or on the policy under the caption:—''Provisions Specially Applicable to this Combination Policy'' or such other distinctive caption as the commissioner may prescribe.

Such policies shall be subject to the first to sixth, inclusive, and ninth clauses, of said section ninety-nine, except as otherwise provided herein and except that there may be printed on or in said policies or on the filing-back thereof such device or devices and such distinctive title of the policy as the commissioner may approve, together with the names, locations, dates of incorporation, plan of operation, the amounts of the paid-up capital stock in case of stock companies, and the names of the officers and agents of each such company.