US money market funds reduced their holdings of short-term liabilities of Australian banks during May, a report by Fitch Ratings shows. Fitch said fund exposures to Australian banks declined by 10 per cent on a US dollar basis over the course of April.The funds switched their investments to Japanese and Canadian banks over the month.Overall aggregate exposures to banks in Australia, Canada, and Japan remained steady at 30 per cent of money market fund assets, Fitch said.National Australia Bank remains the bank making the most use of this pool of funds. Fitch said short-term loans to NAB accounted for 3.5 per cent of the assets of the 10 largest funds surveyed for its report. This funding is equal to around US$22 billion.NAB was one of the three largest recipients of US money market funds in May. Bank of Nova Scotia and Barclays also accounted for 3.5 per cent each of fund assets.