AIX rejects AustralianSuper's Perth Airport breach claims THE Australian Infrastructure Fund (AIX) has rejected claims it breached shareholder agreements over the sale of its stake in Perth Airport to the Future Fund. The countrys biggest industry superannuation fund, AustralianSuper, has threatened legal action against the Future Fund for unlawful conduct in acquiring the 30 per cent stake in Perth Airport as part of its deal to acquire all the assets of AIX in a $2 billion deal agreed last year.