...Fitch Ratings' two-notch upgrade to Ontario International Airport Authority's (OIAA) outstanding airport revenue bonds to 'A+' reflects rapidly strengthening financial performance, driven by robust enplanement growth and a new airline use and lease agreement (AUL). The AUL allows the airport to retain a portion of net ground transportation revenue and all revenue from an onsite real estate development. Fitch resolved the prior Rating Watch Positive following the release of a detailed multiyear capital improvement plan (CIP) and debt issuance plans. These plans indicate that recent financial improvements will be maintained at a level consistent with the upgrade, despite planned new-money debt issuance. A third-party feasibility study also provided greater clarity on the benefits of the airport's new AUL. The 'A+' rating reflects strong financial metrics, a well-structured AUL with robust downside protections and the airport's high growth potential within the greater Southern California market....