Standard & Poor's last week affirmed its 'AA-/Stable' financial strength ratings on Genworth Financial Mortgage Insurance Pty Ltd, the main operating entity for the mortgage insurance business of Genworth in Australia. The affirmation reflects S&P's view that the downgrade of the rating on Genworth Australia's partial reinsurer, Genworth Mortgage Insurance Corp. to 'BBB-/Negative' from 'BBB+/Watch Neg' (published by S&P on 22 December 2009) is tolerated under Genworth Australia's existing rating.Elsewhere in the structured finance sector Fitch Ratings updated several ratings on loan pools originated by Bluestone Mortgages.Taking into account the progressive paydown of outstandings and decreasing arrears levels, Fitch upgraded various middle ranking tranches of RMBS issued by: Sapphire II NZ Series 2005-1; Sapphire II NZ Series 2006-1; Sapphire IX Series 2006-1; Sapphire VI Series 2004-2; Sapphire VIII Series 2005-2; Sapphire X Series 2007-1; Sapphire VII Series 2005-1E. Fitch downgraded, by two notches, the Class BZ and CA notes issued by Sapphire IV NZ Series 2007-1 Trust due to outstanding carry forward charge-offs on lower ranking tranches and continuing high levels of arrears.