CHICAGO--(BUSINESS WIRE)--Fitch Ratings has upgraded the Issuer Default Ratings (IDR) of Crown Castle International Corp. (Crown) and its subsidiaries to 'BBB-' from 'BB'. In addition, Fitch has upgraded the long-term debt ratings of Crown and its subsidiaries as listed at the end of this release. The Outlook is Stable, resolving the previous Positive Outlook. KEY RATING DRIVERS Crown's ratings reflect the strong recurring cash flows generated from its leasing operations, the robust EBITDA marg