EXHIBIT 10.1

THIRD AMENDMENT

TO THE SPRINT INTERCONNECTION AGREEMENT

This Third Amendment to Interconnection Agreement (“Third Amendment”) is entered by and between Sprint Spectrum L.P., acting in its authority as agent on behalf of and for the benefit of APC PCS, LLC, PhillieCo, L.P., SprintCom, Inc., Sprint PCS License, LLC and WirelessCo, L.P., (collectively “Sprint PCS”), Nextel Operations, Inc, acting in its authority as agent for the benefit of Nextel of California, Inc., Nextel Communications of the MidAtlantic, Inc., Nextel of New York, Inc., Nextel South Corp., Nextel of Texas, Inc., and Nextel West Corp., (collectively “Nextel”), NPCR, Inc. (“Nextel Partners”), iPCS, Inc. (comprised of iPCS Wireless, Inc,, Horizon Personal Communications, Inc. and Bright Personal Communications Services, LLC, and collectively referred to herein as “IPCS”), Sprint Communications Company L.P. (“SCCLP”) (Sprint PCS, Nextel, Nextel Partners, IPCS and SCCLP, are collectively referred to herein as “Sprint”) and Neutral Tandem, Inc. (“Neutral Tandem”). Sprint and Neutral Tandem are further referred to herein individually as a “Party” and collectively as “Parties”.

RECITALS

WHEREAS Neutral Tandem entered into a Master Service Agreement with Nextel of California, Inc., Nextel Communications of the MidAtlantic, Inc. Nextel of New York, Inc., Nextel South Corp., Nextel of Texas, Inc., a Texas corporation and Nextel West Corp. effective May 26, 2004 (the “Nextel MSA”); pursuant to which Neutral Tandem provided such Nextel entities transiting services; and

WHEREAS Neutral Tandem and Sprint Spectrum L.P. entered into an Interconnection Agreement dated July 1, 2004 (“Sprint ICA” or “Agreement”), pursuant to which Neutral Tandem provides Sprint PCS transiting services; and

WHEREAS, on or about November 4, 2005, Neutral Tandem, Sprint Spectrum L.P. and Nextel Operations amended the Sprint ICA to, among other things, provide for Neutral Tandem’s delivery of third-party Internet Protocol (“IP”) originated traffic to Sprint Spectrum and the Nextel entities for termination;

WHEREAS, on or about July 1, 2007, Neutral Tandem and Sprint Spectrum amended the Sprint ICA to, among other things, add SCCLP as a party to the Sprint ICA; and

WHEREAS Neutral Tandem entered into a Master Service Agreement with IPCS, Inc., a Delaware Corporation, which is comprised of IPCS Wireless, Inc, Horizon Personal Communications, Inc. and Bright Personal Communications Services, LLC on June 18, 2009 (the “IPCS MSA”); pursuant to which Neutral Tandem provided IPCS transiting services; and

WHEREAS, notwithstanding the concurrent existence of the Nextel MSA, the Sprint ICA, and the IPCS MSA, since the respective acquisition of the Nextel, Nextel Partners and IPCS entities to become Sprint affiliates, the Parties’ intent has been that Neutral Tandem’s transit services be provided to all such Sprint entities pursuant to the Sprint ICA; and,

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WHEREAS Neutral Tandem has been operating under the assumption that its Local Transit Service (“LTS”) has been provided to each of the Sprint entities under the Sprint ICA; and

WHEREAS, the Parties desire to terminate the Nextel MSA and IPCS MSA, to amend the Sprint ICA to clarify the applicability of the Sprint ICA to each Sprint entity identified herein, and set forth such further amendments to the Sprint ICA as provided in this Third Amendment;

NOW, THEREFORE, the Parties agree as follows:

The foregoing recitals are incorporated by this reference.

Neutral Tandem has been operating under the assumption that it is providing transiting service for Local Traffic to each of the Sprint entities named above under the Sprint ICA and not under the Nextel MSA or IPCS MSA. To avoid any ambiguity, the Parties hereby confirm that Neutral Tandem provides its transiting services for Local Traffic to each of the Sprint entities named above and Sprint will receive such services from Neutral Tandem pursuant to the Sprint ICA. The terms of any other agreement between the Parties regarding transiting services for Local Traffic (referred to in the IPCS MSA as “Local Transit Service”) are hereby confirmed as terminated without any liability except to the extent billed and remaining an undisputed outstanding in the ordinary course of business.

This Third Amendment and the rates provided herein on Schedules A and B will become effective on April 25, 2010, if this Third Amendment is executed by Sprint and delivered to Neutral Tandem on or before the close of business on May 5, 2010. If not signed by Sprint until after the close of business on May 5, 2010, then this Third Amendment will be deemed effective between the Parties on the date executed and delivered by Sprint, and result in Sprint receiving the rates provided herein in the first Neutral Tandem billing cycle after Sprint executes and delivers this Third Amendment to Neutral Tandem. For purposes of this section “delivery” includes delivery by means of electronic mail.

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The Sprint ICA paragraph 2 definition of “Local Traffic” (as previously amended), is deleted from the Sprint ICA and replaced with the following:

The Sprint ICA paragraph 5 is deleted in its entirety and replaced with the following:

The following provisions are added as subsections at the end of the existing Sprint ICA Section 7. “Compensation for Transit Traffic.

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The “Compensation For Termination” provision added by the Parties’ November 4, 2005 amendment to the Sprint ICA is deleted and the following provisions are added as further subsections at the end of the existing Sprint ICA Section “7. Compensation For Termination of Transiting Traffic:”

Except as otherwise modified by this Third Amendment, the Agreement shall remain in full force an effect.

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IN WITNESS WHEREOF, the Parties have caused this Third Amendment to be executed by their respective authorized representatives on this date indicated below:

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Schedule A

Preferred Routing Local Traffic Rate (per minute)

For: Sprint PCS, Nextel, NPCR, Inc., iPCS

The following rates apply based on the relevant time period:

Additional Charges

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Schedule B

Preferred Routing Local Traffic Rate (per minute)

For: SCCLP.

The following rates apply based on the relevant time period:

Additional Charges

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