Exhibit 10.11.3

AMENDMENT NO. 1 TO SECURITIES PURCHASE AGREEMENT

This AMENDMENT NO. 1 TO SECURITIES PURCHASE AGREEMENT (this “Amendment No. 1”),
dated as of October 27, 2006 (the “Execution Date”), to the Securities Purchase
Agreement, dated as of July 26, 2005, among ITC^DeltaCom, Inc., a Delaware
corporation (the “Parent”), Interstate FiberNet, Inc., a Delaware corporation
(the “Issuer”), each of the Subsidiary Guarantors identified on the signature
pages hereto, Tennenbaum Capital Partners, LLC, a Delaware limited liability
company, as agent (the “Agent”), and TCP Agency Services, LLC, a Delaware
limited liability company, as collateral agent (the “Collateral Agent” and
together with the Agent, the “Agents”). Capitalized terms used and not otherwise
defined herein shall have the meanings assigned to them in the Securities
Purchase Agreement (as defined below).

W I T N E S S E T H:

WHEREAS, the Parent, the Issuer, the Subsidiary Guarantors, the New Purchasers
party thereto, the Existing Purchasers party thereto and the Agents entered into
the Securities Purchase Agreement, dated as of July 26, 2005 (as amended,
supplemented, restated or otherwise modified from time to time, the “Securities
Purchase Agreement”), pursuant to which the Existing Purchasers and the New
Purchasers purchased from the Issuer (i) Notes in an aggregate principal amount
of $50,000,000, plus the aggregate amount of capitalized PIK interest on the
Existing Third Lien Notes, and (ii) the Warrants;

WHEREAS, pursuant to the agreement attached hereto as Exhibit A (the “P&H
Agreement”), Business Telecom, Inc., a Guarantor, wishes to refinance the P&H
Note identified on Existing Schedule (as hereinafter defined) 4.01(t) to the
Securities Purchase Agreement with new notes having materially different terms
(such refinancing, the “P&H Refinancing”); and

WHEREAS, pursuant to the Securities Purchase Agreement and the other Purchase
Documents, the Required Holders (or the Agent acting at the direction of the
Required Holders), together with the Issuer, may amend the terms of the
Securities Purchase Agreement to permit the P&H Refinancing;

WHEREAS, subject to and in accordance with the terms and conditions hereinafter
set forth, the Agent, at the direction of the Required Holders, is willing to
amend certain provisions of the Securities Purchase Agreement to permit the P&H
Refinancing;

NOW, THEREFORE, for valuable consideration, the receipt and sufficiency of which
are hereby acknowledged, the parties hereto hereby agree as follows:

 

  I. AMENDMENTS.

Subject to the terms and provisions herein, the provisions set forth in this
Article I shall become effective as of the Execution Date.

--------------------------------------------------------------------------------

Section 1.1. Amendment to the Preamble of the Securities Purchase Agreement. The
first sentence of the preamble of the Securities Purchase Agreement is hereby
amended by replacing “This Securities Purchase Agreement is made and entered
into as of July 26, 2005 (this “Agreement”)” with “This Securities Purchase
Agreement is made and entered into as of July 26, 2005 (as amended as of
October 27, 2006, and as it may thereafter be further amended, supplemented,
restated or otherwise modified from time to time, this “Agreement”).”

Section 1.2. Amendments to Section 1.01 of the Securities Purchase Agreement.
Section 1.01 of the Securities Purchase Agreement is hereby amended by adding
the following definition in the appropriate place in alphabetical order:

“Amendment No. 1” means Amendment No. 1 to Securities Purchase Agreement, dated
as of October 27, 2006, by and among the Parent, the Issuer, the Subsidiary
Guarantors party thereto, the Agent and the Collateral Agent, which Amendment
No. 1 amends this Agreement.

Section 1.3. Amendment to Section 5.02(b) of the Securities Purchase Agreement.
The final sentence in Section 5.02(b) of the Securities Purchase Agreement is
hereby amended and restated in full by deleting it in its entirety and replacing
it with the following:

“Notwithstanding any other provision under this Section 5.02(b), (A) the Parent
and Business Telecom, Inc. may once only incur the Debt and Contingent
Obligations contemplated by the agreement attached hereto as Exhibit J, and
(B) any Obligor may Incur Debt owed to any other Obligor. Notwithstanding
anything contained herein to the contrary, the Debt and Contingent Obligations
contemplated by the agreement attached hereto as Exhibit J shall constitute
Surviving Debt for all purposes of this Agreement.”

Section 1.4. Amendment to Section 5.02(k) of the Securities Purchase Agreement.
Section 5.02(k) of the Securities Purchase Agreement is hereby amended by adding
the following paragraph to the end of such section:

“Notwithstanding any other provision under this Section 5.02(k), the Parent and
Business Telecom, Inc. may once only make the prepayments, amendments,
modifications and changes to the Surviving Debt contemplated by the agreement
attached hereto as Exhibit J.”

Section 1.5. Amendment to the Schedules of the Securities Purchase Agreement.

The Securities Purchase Agreement is hereby amended by supplementing the
existing Schedules thereto (collectively, the “Existing Schedules,” and
individually, an “Existing Schedule”) with the Schedules appended hereto as
Exhibit B (collectively, the “New Schedules,” and individually, a “New
Schedule”). Subject to the terms and provisions herein, references to a
“Schedule” in any Purchase Document dated as of the Execution Date or later
shall be a reference to a New Schedule, unless otherwise specifically provided.

 

2

--------------------------------------------------------------------------------

Section 1.6. Amendment to the Exhibits of the Securities Purchase Agreement. The
Securities Purchase Agreement is hereby amended by attaching the P&H Agreement
thereto as Exhibit J.

 

  II. REPRESENTATIONS AND WARRANTIES.

Section 2.1. Representations and Warranties of the Obligors. To induce the
Purchasers to direct the Agent to enter into this Amendment No. 1, the Obligors
represent and warrant, jointly and severally, to the Agents and the Purchasers
as follows as of the Execution Date:

(a) This Amendment No. 1, the Securities Purchase Agreement as amended hereby,
and the other Purchase Documents to which any Obligor is a party have been duly
authorized, executed and delivered and constitute legal, valid and binding
obligations of each such Obligor party thereto enforceable against each such
Obligor in accordance with its terms.

(b) Neither the execution or delivery by each Obligor of this Amendment No. 1,
nor performance by any of them of this Amendment No. 1 and the Securities
Purchase Agreement shall (i) contravene such Obligor’s charter or bylaws,
(ii) violate any law, rule, regulation (including, without limitation,
Regulation X of the Board of Governors of the Federal Reserve System), order,
writ, judgment, injunction, decree, determination or award, (iii) conflict with
or result in the breach of, or constitute a default under, any loan agreement,
indenture, mortgage, deed of trust, or material contract, lease or other
instrument binding on or affecting any Obligor, any of its Subsidiaries or any
of their properties or (iv) except for the Liens created under the Purchase
Documents, result in or require the creation or imposition of any Lien upon or
with respect to any of the properties of any Obligor or any of its Subsidiaries.
No Obligor or any of its Subsidiaries is in violation of any such law, rule,
regulation, order, writ, judgment, injunction, decree, determination or award or
in breach of any such contract, loan agreement, indenture, mortgage, deed of
trust, lease or other instrument, the violation or breach of which could be
reasonably likely to have a Material Adverse Effect.

(c) The representations and warranties contained in the Securities Purchase
Agreement are true, correct and complete in all material respects (except that
any representation and warranty that is qualified as to “materiality” or
“Material Adverse Effect” shall be true and correct in all respects) on and as
of the date hereof as if made on the date hereof, except to the extent such
representations and warranties expressly relate to an earlier date, in which
case they were true and correct as of such earlier date, and except that
references to a Schedule in any such representation and warranty shall be deemed
to be a reference to the corresponding New Schedule.

(d) Prior to and after giving effect to this Amendment No. 1, no Default or
Event of Default has occurred or is continuing.

 

3

--------------------------------------------------------------------------------

(e) After giving effect to this Amendment No. 1, the Collateral Documents
continue to create a valid first priority security interest in the Collateral,
securing the payment of the Secured Obligations, and assuming that all filings
delivered to the Collateral Agent on or before the Closing Date have been duly
filed in accordance with the provisions of the Security Agreement and assuming
that all filings required as a result of the operation of Section 9-507(c) of
the UCC (as defined in the Security Agreement) have been duly filed, such first
priority security interest shall continue to be perfected. The Obligors are the
legal and beneficial owners of the Collateral free and clear of any Lien, except
for the Liens and security interests created or permitted under the Purchase
Documents.

(f) After giving effect to this Amendment No. 1, the Guaranties in favor of the
Secured Parties, granted pursuant to the Purchase Documents, shall continue to
be valid and enforceable against the respective Subsidiary Guarantors
thereunder.

(g) Each Obligor is and, after giving effect to the transactions contemplated
hereby, shall be Solvent. No transfer of Property is being made by the Parent or
any of its Subsidiaries, and no obligation is being incurred by the Parent or
any of its Subsidiaries in connection with the transactions contemplated by this
Amendment No. 1 or the other Purchase Documents with the intent to hinder,
delay, or defraud either present or future creditors of the Parent and its
Subsidiaries.

 

  III. CONDITIONS PRECEDENT.

Section 3.1. Conditions Precedent to Execution Date Amendments. The provisions
of Article I of this Amendment No. 1 shall not become effective unless all of
the following conditions precedent shall have been satisfied or waived before
the Execution Date, or such earlier time specifically provided:

(a) Amendment No. 1; Consent and Authorization. On or prior to the Execution
Date, the Agent shall have received by hand, courier, mail, email or facsimile
transmission (i) duly executed counterparts to this Amendment No. 1 which, when
taken together, bear the authorized signatures of the Parent, the Issuer and the
Subsidiary Guarantors, and (ii) duly executed consents and/or authorizations
from the Required Holders consenting to the matters set forth herein.

(b) Representations and Warranties; Performance; No Default. The representations
and warranties of the Obligors contained in this Amendment No. 1 and the
Securities Purchase Agreement as in effect before the effectiveness of this
Amendment No. 1 shall be true and correct as of the Execution Date (except to
the extent that such representations and warranties expressly relate to an
earlier date, in which case they were true and correct as of such earlier date,
and except that references to a Schedule in any such representation and warranty
shall be deemed to be a reference to the corresponding New Schedule); the
representations and warranties of the Obligors contained in the other Purchase
Documents shall be true and correct as of the Execution Date (except to the
extent that such representations and warranties expressly relate to an

 

4

--------------------------------------------------------------------------------

earlier date, in which case they were true and correct as of such earlier date,
and except that references to a Schedule in any such representation and warranty
shall be deemed to be a reference to the corresponding New Schedule); the
Parent, the Issuer and the Subsidiary Guarantors shall have performed all
covenants and agreements and satisfied all of the conditions on their part to be
performed or satisfied under this Amendment No. 1 and under the Purchase
Documents at or prior to the Execution Date; and no Default or Event of Default
under any Purchase Document shall have occurred and be continuing.

(c) Waiver. The Agent shall have received a copy of a waiver and amendment
signed by the Required Holders (as defined in the First Lien Note Purchase
Agreement) and dated on or before the Execution Date, pursuant to which such
Required Holders agree to the transactions contemplated by the P&H Agreement
(including the incurrence of Debt and Contingent Obligations as contemplated
thereby), which waiver and amendment shall be reasonably satisfactory to the
Agent.

All documents mentioned in this Article III or elsewhere in this Amendment No. 1
shall be deemed to be in compliance with the provisions hereof only if they are
in form and substance satisfactory to counsel for the Agents.

 

  IV. NO PREJUDICE OR WAIVER; REAFFIRMATION.

Section 4.1. No Prejudice or Waiver. The terms of this Amendment No. 1 shall not
operate as a waiver by the Agent, the Collateral Agent or the Purchasers of, or
otherwise prejudice the Agent’s, the Collateral Agent’s or the Purchasers’
rights, remedies or powers under the Purchase Documents or under any applicable
law. No terms or provisions of any Purchase Document, except insofar as this
Amendment No. 1 amends the Securities Purchase Agreement, are waived, modified
or changed by this Amendment No. 1, and the terms and provisions of the Purchase
Documents shall continue in full force and effect

Section 4.2. Acknowledgements and Reaffirmations.

(a) On and after the Execution Date, each reference in the Purchase Documents to
the “Securities Purchase Agreement” shall be deemed to be a reference to the
Securities Purchase Agreement as amended by this Amendment No. 1.

(b) Each Obligor hereby acknowledges and reaffirms all of its obligations and
duties under the Purchase Documents as to all of the Notes and the Warrants.

(c) Each Obligor hereby acknowledges and reaffirms that the Collateral Agent has
and shall continue to have valid, secured, Liens in the Collateral, as set forth
in the Purchase Documents as to all of the Notes.

(c) Each Obligor hereby acknowledges and reaffirms all of its obligations and
duties under Article VII of the Securities Purchase Agreement.

 

5

--------------------------------------------------------------------------------

  V. TERMINATION.

Section 5.1. Termination. If, after December 31, 2006, the P&H Refinancing shall
not have been consummated, the Agent may, upon written notice to the Parent,
terminate this Amendment No. 1 at any time. If this Amendment No. 1 is
terminated pursuant to this Section 5.1, this Amendment No. 1, and the
amendments contemplated hereby, shall forthwith become void ab initio and there
shall be no further obligations on the part of any party hereto with respect to
this Amendment No. 1.

 

  VI. MISCELLANEOUS.

Section 6.1. Governing Law. This Amendment No. 1 shall be construed and enforced
in accordance with, and the rights of the parties shall be governed by, the law
of the State of New York excluding choice-of-law principles of the law of such
State that would require the application of the laws of a jurisdiction other
than such State.

Section 6.2. Counterparts. This Amendment No. 1 may be executed in any number of
counterparts and by the different parties hereto on separate counterparts, each
of which when so executed and delivered shall be an original, but all of which
shall together constitute one and the same instrument. A set of counterparts
executed by all the parties hereto shall be lodged with the Issuer and the
Agent.

Section 6.3. Headings Descriptive. The headings of the several sections and
subsections of this Amendment No. 1 are inserted for convenience only and shall
not in any way affect the meaning or construction of any provision of this
Amendment No. 1.

Section 6.4. Waivers and Consents. Neither this Amendment No. 1 nor any term
hereof may be changed, waived, discharged or terminated orally, or by any action
or inaction, but only by an instrument in writing signed in accordance with the
amendment and waiver provisions set forth in the Securities Purchase Agreement.

Section 6.5. Survival. All warranties, representations, certifications and
covenants made by or on behalf of the Parent, the Issuer and/or the Subsidiary
Guarantors herein or in any of the other Purchase Documents or in any
certificate or other instrument delivered pursuant hereto or pursuant to any
other Purchase Document shall be considered to have been relied upon by the
Agent, the Collateral Agent and the Purchasers and shall survive the execution
hereof and of the other Purchase Documents, regardless of any investigation made
by or on behalf of the Agent, the Collateral Agent or the Purchasers. All
statements in any such certificate or other instrument shall constitute
representations and warranties of the Issuer and/or such Subsidiary Guarantors
hereunder.

Section 6.6. Purchase Documents. This Amendment No. 1 and all other documents
executed in favor of the Agent, the Collateral Agent and/or the Purchasers in
connection herewith shall be deemed to be Purchase Documents for all purposes
under the Securities Purchase Agreement.

Section. 6.7. Further Assurances. Each party hereto agrees that, from time to
time upon the written request of any other party hereto, such party will execute
and deliver such further documents and do such other acts and things as such
other party may reasonably request in order fully to effectuate the purposes of
this Amendment No. 1.

 

6

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, the parties hereto have caused this Amendment No. 1 to be
duly executed and delivered by their respective officers thereunto duly
authorized as of the date first written above.

 

TENNENBAUM CAPITAL PARTNERS, LLC,

    as Agent

TCP AGENCY SERVICES, LLC,

    as Collateral Agent

Each of the above by:

/s/ Howard Levkowitz

Name:  Howard Levkowitz Title:    Managing Partner

--------------------------------------------------------------------------------

INTERSTATE FIBERNET INC., as Issuer By:  

/s/ Richard E. Fish

Name:   Richard E. Fish Title:   Chief Financial Officer ITC^DELTACOM, INC., as
Guarantor By:  

/s/ Richard E. Fish

Name:   Richard E. Fish Title:   Chief Financial Officer

DELTACOM, INC. (formerly known as

ITC^DeltaCom Communications, Inc.), as Guarantor

By:  

/s/ Richard E. Fish

Name:   Richard E. Fish Title:   Chief Financial Officer DELTACOM INFORMATION
SYSTEMS, INC., as Guarantor By:  

/s/ Richard E. Fish

Name:   Richard E. Fish Title:   Chief Financial Officer

--------------------------------------------------------------------------------

BTI TELECOM CORP., as Guarantor By:  

/s/ Richard E. Fish

Name:   Richard E. Fish Title:   Chief Financial Officer BUSINESS TELECOM, INC.,
as Guarantor By:  

/s/ Richard E. Fish

Name:   Richard E. Fish Title:   Chief Financial Officer BUSINESS TELECOM OF
VIRGINIA, INC., as Guarantor By:  

/s/ Richard E. Fish

Name:   Richard E. Fish Title:   Chief Financial Officer