[This headnote is not to be read as part of the judgment]
The appellant, Commonwealth Steel Company Ltd sought indemnity from the respondent, BHP Billiton Marine & General Insurance Ltd under a contract of insurance indemnifying employers for common law liability for a period of risk from 31 March 1978 to 31 March 1979. The appellant claimed $466,463 under the policy as a consequence of a settlement between the appellant and a former employee in respect of common law liability arising from the employee's exposure to asbestos fibres.
Where the insurance contract was made the appellant and the respondent (known then as Hematite Insurances Pty Ltd) were both subsidiaries of the same parent company. The respondent was established by the parent company as a captive insurer for the companies within the parent company's group. It was to arrange reinsurance. On 10 May 1977, the first policy was issued for the period of 31 March 1977 to 31 March 1978 and provided that:
"This Policy is only to pay the excess of $125,000 (indexed in accordance with attached Stability Clause). Ultimate Net Loss in respect of each disaster (hereinafter termed 'the Primary Limit') up to a further $920,000 in respect of each and every disaster, unlimited in all".
Also on 10 May 1977, an endorsement of this policy incorporated a Primary Limit Stability Clause which provided the method of calculating indexation so as to retain the relative value of the policy to that which existed at 31 March 1976. A renewal certificate dated 28 April 1978 provided for renewal of cover for the relevant period from 31 March 1978 to 31 March 1979. An endorsement was issued on 1 May 1978 and provided that:
"The sum insured under the policy shall be $1,000,000 but the Insured will pay the first $125,000 (indexed in accordance with the attached Stability Clause) of each and every disaster unlimited in number of each policy year."
There was no attached Stability Clause separate from the clause in the endorsement of 10 May 1977.
The issue was whether the deductible of $125,000 or the limit of $1,000,000 was to be indexed in accordance with the Primary Limit Stability Clause. The primary judge preferred the former construction on the basis of the proper construction of the policy. Hammerschlag J held that the surrounding circumstances provided an additional layer of support to this finding. Commonwealth Steel appealed.
The Court (Beazley ACJ, Meagher and White JJA) dismissed the appeal and held:
- The extrinsic circumstances demonstrated that the deductible was to be indexed. These circumstances demonstrated that the commercial aim of the indexation was to secure reinsurance. The evidence established that reinsurers required the deductible to be indexed. The evidence also established that when the parties used the phrase Primary Limit in the context of the Stability Clause they were referring to the deductible. The evidence provided objective background facts known to both parties: [6], [34]-[36], [45] (per White JA, Beazley ACJ and Meagher JA agreeing).
- The position of the index reference immediately after the words "excess of $125,000" and para (a) of the Stability Clause recorded an intention that indexation apply to the excess, not the sum insured: [8] (per Meagher JA, Beazley ACJ agreeing).