Most of the rise in delinquent business loans on the books of Australian banks relates to property-related lending, the Reserve Bank of Australia said in the half-yearly Financial Stability Review.The RBA said the arrears rate for loans to incorporated businesses increased to 1.2 per cent at June 2008, up from 0.7 per cent at December 2007. The RBA drew on APRA data for the estimate.The RBA said the arrears rate on loans to unincorporated businesses has not risen over the past year.For both incorporated and unincorporated business, the RBA said arrears levels were similar to those in 2003 and 2004.