Form 6-K Filing Summary

This Form 6-K filing contains legal opinions from U.S. counsel (Sullivan & Cromwell LLP) and Canadian counsel (Osler, Hoskin & Harcourt LLP) regarding the issuance of US$1,250,000,000 aggregate principal amount of Bank of Montreal's 5.099% Fixed/Floating Rate Senior Notes due 2030. The U.S. counsel opines on the validity and enforceability of the notes under U.S. federal and New York state laws, subject to general bankruptcy and equity principles. The Canadian counsel opines on the validity and enforceability of the notes and the related indenture under Ontario and Canadian federal laws, subject to specific qualifications related to Canadian laws such as the Bank Act, the Winding-up and Restructuring Act, and the limitations act. Both counsels provide their consent for the filing of these opinions as exhibits to the Form 6-K, which is incorporated by reference into the Bank's Form F-3 registration statement.