The significance to Australian banks  of the shifting investment stance of US money market funds - which are under pressure from flighty investors - received attention in a survey of bank funding issues by the Reserve Bank of Australia's assistant governor, Guy Debelle, yesterday.In a talk to the annual congress of the Finance & Treasury Association in Sydney, Debelle reviewed issues affecting European banks amid the drawn-out negotiations over managing the stressed public finances of low income countries - and the consequences for banks in high income countries.One consequence for banks in Australia is that one class of investor in bank debt - US money market funds - has picked up markedly over recent months."In contrast to the recent experience of some European banks, the Australian banks have found that US MMFs have been more than willing to maintain their exposures, including at longer maturities," Debelle said. "Indeed, recently the Australian banks have been beneficiaries of a reallocation by the MMFs away from the European banks."Data compiled by Fitch Ratings, and republished last week by Citigroup Global Markets, puts the percentage of holdings of prime US money market funds invested in the debt of Australian banks at around nine per cent. This is up from around seven per cent in late 2010. Around the time of the 2007 credit crunch (which morphed into the financial crisis) the percentage of Australian bank debt in money market funds was around four per cent. Earlier in the 2000s these funds held little local bank debt.Sean Keane, author of a daily credit commentary for Credit Suisse, yesterday cited "various market estimates of a pick-up in Australian bank US dollar commercial paper issuance over the past four months, with some suggesting that volumes have increased by three to five per cent."The RBA's Debelle otherwise noted that there was "little sign of strain or counter-party concern in the local interbank market". Banks are also now eligible to sell covered bonds. Several reports over the last day suggest that National Australia Bank and Commonwealth Bank have already set up investor roadshows. Reuters reports that NAB may sell the bonds in the US144a market.Debelle also reminded his audience that "if they experience increased difficulty in accessing US funding markets, this is resolved by sourcing Australian dollar liquidity, including, in stressed circumstances, from the Reserve Bank."