PROSPECTUS SUPPLEMENT (TO PROSPECTUS AND PROSPECTUS SUPPLEMENT EACH DATED MAY 16, 1997)

MERRILL LYNCH & CO., INC. MEDIUM-TERM NOTES, SERIES B DUE NINE MONTHS OR MORE FROM DATE OF ISSUE CONSTANT MATURITY TREASURY RATE INDEXED NOTES

Principal Amount: $62 million Interest Reset Dates: Each Interest Payment Date up to and including March 27, 2000 Original Issue Date: June 27, 1997 Interest Rate Basis: Constant Maturity Treasury Rate Maturity Date: June 27, 2000 Designated CMT Maturity Index: Two-year Redemption Date: Not Applicable Spread: +.03% Optional Repayment Dates: Not Applicable Designated CMT Telerate Page: 7055 Interest Payment Dates: Each March 27, June 27, September 27 and December 27, commencing September 27, 1997

DESCRIPTION OF THE NOTES GENERAL The Medium-Term Notes, Series B of Merrill Lynch & Co., Inc. (the "Company"), offered hereby are "Constant Maturity Treasury Rate Indexed Notes" and are referred to in this Prospectus Supplement as the "Notes". The Notes are Regular Floating Rate Notes and certain provisions of the Notes are more fully described in the accompanying Prospectus and Prospectus Supplement. This Prospectus Supplement relates to $62,000,000 aggregate principal amount of Notes which the Company has agreed to sell to Merrill Lynch, Pierce, Fenner & Smith Incorporated (the "Underwriter"), and which the Underwriter has agreed to purchase from the Company, at a price of 99.807% of the principal amount thereof. The Underwriter has advised the Company that it proposes initially to offer the Notes to the public at a public offering price equal to 100% of the principal amount thereof. After the initial public offering, such public offering price may be changed. The Notes will not be subject to redemption by the Company in whole or in part prior to the Maturity Date. INTEREST The Notes will bear interest from and including June 27, 1997 to but excluding the Maturity Date. Interest will be payable on the Interest Payment Dates specified above. The interest rate will be reset on each Interest Reset Date specified above to a per annum rate equal to the Constant Maturity Treasury Rate (as defined herein) plus 0.03%, as determined by Merrill Lynch Capital Services, Inc. (the "Calculation Agent"), a subsidiary of the Company; provided, however, that the per annum rate of interest payable on the Notes for the period from and including June 27, 1997 to but excluding September 27, 1997 will be calculated using June 25, 1997 as the relevant Interest Determination Date. The "Interest Determination Date" pertaining to an Interest Reset Date will be the second Business Day preceding such Interest Reset Date. Interest on the Notes will be computed on the basis of a 360-day year of twelve 30-day months. The date of this Prospectus Supplement is June 20, 1997