**Exhibit 10.4****CONFIDENTIAL PORTIONS OF THIS DOCUMENT HAVE BEEN REDACTED AND FILED SEPARATELY WITH THESECURITIES AND EXCHANGE COMMISSION****FIRST AMENDMENT TO DARK FIBER IRU AGREEMENT**This First Amendment to Dark Fiber IRU Agreement (“*Amendment*”) is between MetropolitanFiber Systems of New York, Inc. (“*MFS*”), and RCN Telecom Services, Inc. (“*RCN*”), assuccessor-in-interest to RCN Telecom Services of New York, Inc.WHEREAS, MFS and RCN Telecom Services of New York, Inc., the predecessor of RCN, entered intoa Dark Fiber IRU Agreement dated May 8, 1997 (the “*Agreement*”); andWHEREAS, RCN hereby elects to renew the Agreement for five years pursuant to the option toextend, as set forth in Section 25.b. of the Agreement; andWHEREAS, MFS has agreed to accept, and RCN shall pay, a one time, all inclusive payment forsuch extension, which will satisfy RCN’s payment obligations under the Agreement and thisAmendment, including, but not limited to Recurring Charges and WorldCom’s Maintenance Costs.**NOW THEREFORE**, in consideration of the terms set forth in this Amendment, MFS and RCN agree asfollows:1. Definitions. All capitalized terms not otherwise defined herein shall havethe meanings ascribed to them by the Agreement.2. Term. Section 11 of the Agreement is hereby deleted in its entirety andreplaced with the following:11. **Term**. The “Term” is hereby defined as being the periodwhich commences on the date of this Agreement and which ends onDecember 31, 2011 unless earlier terminated pursuant to the terms ofthis Agreement. The period of time from January 2, 2007 throughDecember 31, 2011 shall be referred to herein as the “Renewal Term.”3. Renewal Fee. In consideration for the extension of the Agreement for five(5) years, RCN hereby agrees to pay to MFS a one time fee for the entire Renewal Term of******* (“Renewal Fee”). The Renewal Fee shall be paid to MFS withinthirty (30) days after receipt by RCN of an invoice from MFS for such fee. Payment of theRenewal Fee shall fully satisfy RCN’s obligations pursuant to Sections 18.b.(i) and (ii) ofthe Agreement for the Renewal Term, and RCN shall not have any additional obligation for Sections 18.b.(i) and (ii) beyond the Renewal Fee. There are no maintenance feesto be incurred or paid by RCN under this Amendment. All other payment obligations in theAgreement shall remain the same through the Renewal Term. * Confidential material which has been omittedand filed separately with the Securities and Exchange Commission.
 
 

 
4. Dedicated Fibers. The definition of “Dedicated Fibers” in the Agreementshall be modified by this Amendment and after the Amendment Effective Date shall consistsolely of those certain designated fibers within the WorldCom Facilities as moreparticularly described in the attached Revised Exhibit 5. Any Dedicated Fibers in RCN’spossession that are not listed on the Revised Exhibit 5 have been relinquished by RCN andhave been or will be returned to MFS within 30 days of final execution of this Amendment(“Relinquished Fibers”). After thirty (30) days following the execution of this Amendment,RCN shall only utilize the Dedicated Fibers set out in the Revised Exhibit 5.5. Relinquished Fiber Process and Timeframe.a) The parties shall cooperate and work together in good faith in order to help ensurethe Relinquished Fibers are fully accessible and capable of being used by MFS within ninety(90) days following the execution of this Amendment; provided that RCN can request, and MFSshall approve an extension of this 90 day period for a commercially reasonable period oftime for good cause shown, not to exceed ninety (90) additional days, except as otherwisemutually agreed upon. Except as otherwise mutually agreed upon by the parties, allRelinquished Fiber shall be returned to MFS’s use within one hundred eighty (180) daysfollowing the execution of this Amendment.b) The parties agree that the process by which RCN shall relinquish the WorldCom Fibershall primarily involve resplicing fiber back into the Verizon/MFS network. The partiesagree to proceed with this effort according to the following:i) On or before December 20, 2007, RCN shall deliver to MFS a proposed project planand schedule providing an outline of RCN’s resplicing plan. This RCN resplicingproject plan will identify the fibers to be relinquished along with the Verizon/MFSsplice cases to be affected, and shall identify a preliminary timeframe for RCN’sproposed efforts. MFS shall review the RCN proposal and provide input andcomments back to RCN (including an estimate of costs that MFS proposes would bereimbursed by RCN) within 10 business days following receipt of the plan. Theparties shall thereafter work together and in good faith to finalize a resplicingplan that accommodates the operational needs and limitations of both parties. Theparties acknowledge that the resplicing plan may need to be modified and adjusted ona periodic basis, and shall work together in good faith to facilitate any neededmodifications, and minimize any associated costs.
 
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ii) RCN shall begin resplicing work as soon as practicable following the executionof this First Amendment. RCN shall notify MFS no less than five (5) days prior tothe time it intends to access Verizon/MFS splice cases for the purposes ofresplicing Relinquished Fiber. Notice shall be provided to permit MFS to have oneor two MFS representatives present at the time RCN accesses the splice caseand performs the resplicing. Such representatives shall supervise the work and helpensure that the resplicing occurs according to commercially reasonable qualitystandards. The parties agree that, except in unusual circumstances, no more thantwo MFS representatives would need to be present for this work.