Dominant competitive position in Ireland. Favorable regulatory regime. Significant cash retained on balance sheet, supporting credit metrics. Stressed macroeconomic environment in Ireland, creating uncertainty around traffic recovery. Cash flow metrics toward the bottom of the range for the rating. The ratings on Irish airport operator Dublin Airport Authority (DAA) reflect Standard&Poor's Ratings Services' view of the dominant position of Dublin Airport--which generates three quarters of the DAA group's EBITDA--in the Irish air transportation market and its favorable single-till regulatory regime, which has supported significant increases in aeronautical tariffs in 2010 (up 26%) and 2011 (up 7%) that offset declines in traffic. We also view DAA's implementation of cost-cutting initiatives and its moderate requirements for capital works from 2011