Sec Form 4 Filing - M/C VENTURE PARTNERS VI L P @ Zayo Group Holdings, Inc. - 2014-10-22

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person M/C VENTURE PARTNERS VI L P 2. Issuer Name and Ticker or Trading Symbol Zayo Group Holdings, Inc. [ ZAYO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O M/C PARTNERS, 75 STATE STREET, SUITE 2500 3. Date of Earliest Transaction (MM/DD/YY) 10/22/2014 (Street) BOSTON, MA02109 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 10/22/2014 S 1,399,041 D $ 17.9788 24,038,604 I See Footnotes ( 1 ) ( 2 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other M/C VENTURE PARTNERS VI L P C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 BOSTON, MA02109 X M/C Venture Partners, LLC C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 BOSTON, MA02109 X M/C VP VI, L.P. C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 BOSTON, MA02109 X M/C Venture Investors LLC C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 BOSTON, MA02109 X M/C Venture Partners V, L.P. C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 BOSTON, MA02109 X M/C VP V, LLC C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 BOSTON, MA02109 X Chestnut Venture Partners LP C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 BOSTON, MA02109 X Chestnut Street Partners Inc C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 BOSTON, MA02109 X Signatures M/C VENTURE PARTNERS VI, L.P., By: M/C VP VI, LLC, its general partner, By: M/C Venture Partners, LLC, its general partner, By: /s/ Gillis S. Cashman, Manager 10/23/2014 Signature of Reporting Person Date M/C VP VI, LLC, By: M/C Venture Partners, LLC, its general partner, By: /s/ Gillis S. Cashman, Manager 10/23/2014 Signature of Reporting Person Date M/C VENTURE PARTNERS, LLC, By: /s/ Gillis S. Cashman, Manager 10/23/2014 Signature of Reporting Person Date M/C VENTURE INVESTORS L.L.C., By: /s/ Gillis S. Cashman, Manager 10/23/2014 Signature of Reporting Person Date M/C VENTURE PARTNERS V, L.P., By: M/C VP V, LLC, its general partner, By: /s/ Gillis S. Cashman, Manager 10/23/2014 Signature of Reporting Person Date M/C VP V, LLC, By: /s/ Gillis S. Cashman, Manager 10/23/2014 Signature of Reporting Person Date CHESTNUT VENTURE PARTNERS, L.P., By: Chestnut Street Partners, Inc., its general partner, By: /s/ David D. Croll, President 10/23/2014 Signature of Reporting Person Date CHESTNUT STREET PARTNERS, INC., By: /s/ David D. Croll, President 10/23/2014 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Following the reported transaction, consists of (i) 23,314,888 shares held of record by M/C Venture Partners VI, L.P., (ii) 723,716 shares held of record by M/C Venture Investors L.L.C., (iii) no shares held of record by M/C Venture Partners V, L.P. and (iv) no shares held of record by Chestnut Venture Partners, L.P. (together, the "M/C Shareholders"). M/C VP VI, L.P. is the sole general partner of M/C Venture Partners VI, L.P. and M/C Venture Partners, LLC is the sole general partner of M/C VP VI, L.P. M/C VP V LLC is the sole general partner of M/C Venture Partners V, L.P. (continued) ( 2 )(continued from footnote 1) Chestnut Street Partners, Inc. is the sole general partner of Chestnut Venture Partners, L.P. As the Managers of M/C Venture Partners, LLC, M/C Venture Investors L.L.C. and M/C VP V LLC, Gillis S. Cashman, Brian M. Clark, David D. Croll, James F. Wade and John W. Watkins collectively have direct or indirect investment and voting authority over the securities held by M/C Venture Partners VI, L.P., M/C Venture Investors L.L.C. and M/C Venture Partners V, L.P. David D. Croll and James F. Wade collectively have investment and voting authority over the securities held by Chestnut Venture Partners, L.P. Each of the foregoing entities and individuals disclaims beneficial ownership of the shares held of record by the M/C Shareholders, except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the reporting person is the beneficial owner of the securities for purposes of Section 16 or for any other purpose.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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