In an unusual move, Infratil took a bet on the S&P500 Index falling and made $45 million.
The specialised infrastructure investor said the taking of put options on the S&P500 index were an "insurance" policy.
"This is as an unusual arrangement for an infrastructure company but it reflects the concern management and directors held for the health of the global capital markets," the company said in releasing its interim profit report for the six months to September 30.
The company first took out the options around 18 months ago and has now shut them down because they became too expensive.
The company is not getting into the business of trading financial instruments but took the view 18 months ago that a large financial event was possible and took some insurance out against it.
During the interim period, Infratil recorded a cash gain of $16 million from put options purchased against the S&P500 index.
This insurance arrangement was terminated in October and resulted in further cash gains of $17m, which will be recorded in the second half of the 2009 financial year.
Infratil reported earnings before interest, tax, depreciation, amortisation and revaluations of $203m in the six month period, up from $166 million for the same period last year.
It declared a dividend of 2.5 cents per share, which is unchanged from last year, and is to be paid on December 15 to all shareholders on the register on December 5. Earnings after interest, depreciation and amortisation of $67m, were up from $59m.
The net surplus after tax of $7.3m was down from $14.5m last year due to a $13.4m reduction in derivative valuations.
The company's investment in TrustPower contributed $136.7m against $116.2m last year.
Wellington Airport contributed $32.2m against $27.7m last year.
Infratil Energy Australia earned $28.1m, against $7.8m last year and NZ Bus contributed $17.8m against $20.8m last year.
The company said its return to shareholders was not satisfactory at negative 4 percent, but global developments were clearly at play in determining Infratil's share price.
