Deutsche Bank, one of only three banks with triple-A ratings from all the major agencies, has been placed under review for possible downgrade by Moody's Investors Service.
Moody's cited the bank's sluggish domestic operations and its rapid international expansion.
The agency said it will reconsider Deutsche Bank's senior triple-A long- term debt and deposit ratings and its triple-A counterparty rating. Moody's is also reviewing the single-A financial strength rating of Deutsche Bank AG, the Frankfurt-based banking group's main operating unit.
Deutsche Bank, together with Amsterdam-based Rabobank Nederland and Union Bank of Switzerland, are the only major banks that have retained triple-A ratings.