17.—The following subsection is substituted for subsection (2) of section 56 of the Principal Act:

“(2) The insurance required by this section may be subject to the following limitation and the following exception or either of them—

(a) it may, in so far as it relates to injury to property, be limited to the sum of €200,000 in respect of injury caused by any one act of negligence or any one series of acts of negligence collectively constituting one event,

(b) there may be excepted from the liability covered thereby any liability (in excess of the common law or the statutory liability applicable to the case) undertaken by the insured or the principal debtor by special contract.”.