MELBOURNE (Standard&Poor's) May 5, 2011--Standard&Poor's Ratings Services said today that its ratings on National Australia Bank Ltd. (NAB: AA/Stable/A-1+) are unchanged following NAB's announcement of its results for the first-half ended March 31, 2011. "NAB reported overall improved results for its 2011 fiscal half year, which were in-line with Standard&Poor's expectations at the current rating level," said Standard&Poor's credit analyst Gavin Gunning. However, we believe that asset quality is likely to remain challenging for NAB in the short-to-medium term. Further, funding is seen by Standard&Poor's as a relative weakness for NAB and other major Australian banks, by international standards, at their current rating levels. Mr. Gunning added: "We will also