A mutual company organized under chapters 17 to 33 of this title (s. 17:17-1 et seq.), may borrow or assume a liability for the repayment of a sum of money sufficient to defray the reasonable expenses of its organization, or to enable it to comply with any requirement of law or as a guaranty fund upon agreement, which shall first be submitted to and approved by the commissioner, that the loan or advance, with interest at a rate not exceeding six per cent per annum, shall be repaid only out of the surplus, earnings or profits of the corporation with the approval of the commissioner whenever, in his judgment, its financial condition shall warrant. The commissioner’s approval shall not be withheld if after the repayment is made the company has and is in possession of a surplus equal to ten per cent or more of its gross annual premiums on policies outstanding and in force. Any such loan or advance shall not form a part of the legal liabilities of the company, but until repaid all statements published or filed with the commissioner by the company shall show the amount thereof then unpaid.