Exhibit 10.1

AMENDMENT OF LEASES

This Agreement (“Agreement”), dated as of April 4, 2007, between 60 HUDSON OWNER
LLC (successor to Westport Communications LLC and Hudson Telegraph Associates,
L.P., formerly known as Hudson Telegraph Associates), a Delaware limited
liability company, having an office c/o Williams Real Estate Co. Inc., 380
Madison Avenue, New York, New York 10017 (“Landlord”), and FIBERNET EQUAL
ACCESS, LLC, a New York limited liability company, having offices at 570
Lexington Avenue, New York, NY 10022 (“Tenant”).

W I T N E S S E T H:

WHEREAS:

(A) Landlord and Tenant are the current parties to an agreement of lease, dated
as of February 17, 1998, as thereafter amended on numerous occasions (as so
amended, the “Existing 19/12 Lease”), pursuant to which Landlord presently
leases to Tenant and Tenant presently leases from Landlord portions of the 19th
and 12th floors, the basement and lower mezzanine at Landlord’s building known
as 60 Hudson Street, New York, New York (“Building”);

(B) Landlord and Tenant also are the current parties to an agreement of lease,
dated as of April 1, 2001, as thereafter amended on numerous occasions (as so
amended, the “Existing Ground Floor Lease”), pursuant to which Landlord present
leases to Tenant and Tenant presently leases from Landlord portions of the
ground floor and basement at the Building;

(C)(i) Tenant’s security deposit under the Existing 19/12 Lease is presently in
the form of a letter of credit issued by Deutsche Bank and is in the amount of
$783,365.00 (“Existing 19/12 LC”); and

(ii) Tenant’s security deposit under the Existing Ground Floor Lease is
presently in the form of a letter of credit issued by Deutsche Bank and is in
the amount of $3,950,000.00 (“Existing Ground Floor LC”); and

(D) Tenant has requested that Landlord accept replacements of the Existing 19/12
LC and the Existing Ground Floor LC, to be issued by Bank of America
(“Replacement LCs”), and Landlord is only prepared to accept the Replacement LCs
upon and subject to the terms and conditions hereinafter set forth.

NOW, THEREFORE, for good and valuable consideration, the receipt and sufficiency
of which hereby is acknowledged, Landlord and Tenant agree as follows:

1. The capitalized terms contained in this Agreement shall, for the purposes
hereof, have the same meanings as are ascribed to them in the Existing 19/12
Lease and the Existing Ground Floor Lease, respectively, unless otherwise
defined herein. As used herein, (a) the term “19/12 Lease” shall mean the
Existing 19/12 Lease, as amended by this Agreement and as hereafter amended, and
(b) the term “Ground Floor Lease” shall mean the Existing Ground Floor Lease, as
amended by this Agreement and as hereafter amended.

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2. To induce Landlord to accept the Replacement LCs, in the forms annexed hereto
as Exhibits A and B, Landlord and Tenant hereby agree that the Existing 19/12
Lease and the Existing Ground Floor Lease shall be modified, respectively, as
follows:

(A) There shall be added to Article 60 of the Existing 19/12 Lease the following
additional provision:

“If, at any time after Landlord, in its sole and absolute judgment exercised in
good faith, determines that it may wish to transfer the Replacement LC annexed
hereto as Exhibit A (“19/12 Replacement LC”) and, in its sole and absolute
discretion exercised in good faith, determines that it will have problems in
effectuating such transfer by reason of the provisions pertaining to the
certifications set forth in the transfer document annexed as Exhibit A to the
Existing 19/12 LC (“Existing 19/12 Transfer Provisions”), Landlord may draw down
the entire amount of the 19/12 Replacement LC and either (i) retain the proceeds
of such draw (“19/12 Draw Proceeds”) for the Security Deposit under the 19/12
Lease, or (ii) arrange for the issuance by a bank satisfactory to Landlord, in
its sole and absolute discretion exercised in good faith, of a replacement for
the 19/12 Replacement LC having the same substantive effect and general form as
the 19/12 Replacement LC except for the Existing 19/12 Transfer Provisions
(“19/12 Alternative LC”), using the 1912 Draw Proceeds as collateral for the
19/12 Alternative LC. In such event, Tenant shall, upon demand, reimburse
Landlord, as additional rent, for the amount by which the cost of obtaining the
19/12 Alternative LC, including the fees and other reasonable costs of issuance,
exceeds the 19/12 Draw Proceeds. Notwithstanding the foregoing, Landlord shall,
if feasible within the time frame determined by Landlord, in its sole and
absolute discretion exercised in good faith, to be necessary for obtaining the
19/12 Alternative LC, afford Tenant the opportunity to furnish a 19/12
Alternative LC from a bank satisfactory to Landlord, in its sole and absolute
discretion exercised in good faith.”

(B) There shall be added to Article 60 of the Existing Ground Floor Lease the
following additional provision:

“If, at any time after Landlord, in its sole and absolute judgment exercised in
good faith, determines that it may wish to transfer the Replacement LC annexed
hereto as Exhibit B (“Ground Floor Replacement LC”) and, in its sole and
absolute discretion exercised in good faith, determines that it will have
problems in effectuating such transfer by reason of the provisions pertaining to
the certifications set forth in the transfer document annexed as Exhibit A to
the Existing Ground Floor LC (“Existing Ground Floor Transfer Provisions”),
Landlord may draw down the entire amount of the Ground Floor Replacement LC and
either (i) retain the proceeds of such draw (“Ground Floor Draw Proceeds”) for
the Security Deposit under the Ground Floor Lease, or (ii) arrange for the
issuance by a bank satisfactory to Landlord, in its sole and absolute discretion
exercised in good faith, a replacement for the Ground Floor Replacement LC
having the same

 

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substantive effect and general form as the Ground Floor Replacement LC except
for the Existing Ground Floor Transfer Provisions (“Ground Floor Alternative
LC”), using the Ground Floor Draw Proceeds as collateral for the Ground Floor
Alternative LC. In such event, Tenant shall, upon demand, reimburse Landlord as
additional rent for the amount by which the cost of obtaining the Ground Floor
Alternative LC, including the fees and other reasonable costs of issuance,
exceeds the Ground Floor Draw Proceeds. Notwithstanding the foregoing, Landlord
shall, if feasible within the time frame determined by Landlord, in its sole and
absolute discretion exercised in good faith, to be necessary for obtaining the
Ground Floor Alternative LC, afford Tenant the opportunity to furnish a Ground
Floor Alternative LC from a bank satisfactory to Landlord, in its sole and
absolute discretion exercised in good faith.”

3. Except as modified by this Agreement, the Existing 19/12 Lease and the
Existing Ground Floor Lease and all covenants, agreements, terms and conditions
thereof shall remain in full force and effect and the Existing 19/12 Lease and
the Existing Ground Floor Lease, as so modified, hereby are ratified, confirmed
and approved.

4. The covenants, agreements, terms and conditions contained in this Agreement
shall bind and inure to the benefit of the parties hereto and their respective
successors and, except as otherwise provided in the 19/12 Lease and the Ground
Floor Lease, their respective assigns.

5. This Agreement may not be changed orally, but only by a writing signed by the
party against whom enforcement thereof is sought.

IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the
day and year first above written.

 

60 HUDSON OWNER LLC By:  

HUDSON TELEGRAPH ASSOCIATES, L.P.,

its managing member

  By:   Sixty Hudson Management LLC, general partner     By:  

 

    Name:       Manager   FIBERNET EQUAL ACCESS, LLC By:  

 

Name:   Title:  

By its execution below, the undersigned acknowledges its agreement to be bound
by this Agreement, the 19/12 Lease and the Ground Floor Lease jointly and
severally with Tenant.

 

FIBERNET TELECOM GROUP, INC. By:  

 

Name:   Title:  

 

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