Credit rating agency Moody\'s downgraded the outlook for Singapore\'s three home-grown banks on Monday from \"stable\" to \"negative,\" citing rapid loan growth and rising real estate prices in Singapore as well as the regional markets. \"These have increased the probability of deterioration in the banks\' credit profiles under potential adverse conditions in the future,\" it said, referring to the banks of DBS, OCBC and UOB. The outlook report covers prospects for the banks in the next 12 to 18 months. Singapore\'s three home-grown banks were ranked among the world\' s 50 safest banks last year, but Moody\'s said the low interest rate and strong regional economic growth in the region has led to rising credit and asset inflation in the property and financial markets. The household debt in Singapore increased to 77.2 percent of the gross domestic product as of March, from 64.4 percent at the end of 2007. The private property prices grew some 120 percent since late 2007. Moody\'s said a tightening of the U.S. monetary policy could be a trigger to interest rate rises in Singapore and neighboring countries as well as capital outflows from emerging economies, which are expected to have an impact on Singapore banks.