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                                                                    EXHIBIT 10.4

Time Warner NY Cable LLC
c/o Time Warner Cable Inc.
290 Harbor Drive
Stamford, CT 06902-6732

                                  June 24, 2005

Adelphia Communications Corporation
5619 DTC Parkway
Greenwood Village, CO 80111
Attn: Brad Sonnenberg

Ladies and Gentlemen:

      Reference is made to the Asset Purchase Agreement between Time Warner NY
Cable LLC, a Delaware limited liability company ("TWNY"), and Adelphia
Communications Corporation, a Delaware corporation ("Adelphia"), dated as of
April 20, 2005, as amended on the date hereof (the "TW Purchase Agreement").
Capitalized terms used but not otherwise defined herein shall have the
respective meanings ascribed to them in the TW Purchase Agreement.

      1. Timing of Effectiveness of the Plan and the Closing. The parties hereto
agree that the condition set forth in Section 6.1(a) of the TW Purchase
Agreement with respect to the effectiveness of the Plan, shall be satisfied by
the Plan becoming effective contemporaneously with the Closing.

      2. Assumption of Effectiveness. In determining whether Sections 6.1(f),
6.2(a), 6.2(b) (except for covenants to the extent related to Adelphia's
obligations to use commercially reasonable efforts to fulfill the conditions
precedent to its obligations under the TW Purchase Agreement), 6.2(d) (to the
extent relating to 6.2(a) and 6.2(b) (except for covenants to the extent related
to Adelphia's obligations to use commercially reasonable efforts to fulfill the
conditions precedent to its obligations under the TW Purchase Agreement)) and
6.2(e) of the TW Purchase Agreement have been satisfied, the parties hereto
shall assume that the Plan is effective in accordance with its terms and shall
assume that any other plan of reorganization relating to any Managed Cable
Entity or any other Transferred Asset as to which the only condition to its
effectiveness that has not been satisfied or waived is the Closing is effective
in accordance with its terms.

      3. Consent to Plan and Disclosure Statement. TWNY hereby acknowledges that
the Plan, all exhibits attached thereto, the Disclosure Statement (except for
the sections of the Disclosure Statement describing the Plan to the extent such
description is inconsistent with the Plan; it being understood that

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TWNY shall promptly following the date hereof inform Adelphia of any such
inconsistency it identifies) and the Disclosure Statement Motion (each of which
is attached hereto) are acceptable in form and substance to TWNY and otherwise
satisfy the requirements of the fourth sentence of Section 5.13(a) of the TW
Purchase Agreement to the extent relating to the Plan, the exhibits attached
thereto, the Disclosure Statement (except for the sections of the Disclosure
Statement describing the Plan to the extent such description is inconsistent
with the Plan) and the Disclosure Statement Motion. TWNY consents to the filing
of such documents with the Bankruptcy Court. Adelphia hereby agrees to waive the
conditions set forth in Sections 13.01(f), 13.01(g) and 13.02(b) of the Plan in
order to effect the confirmation or effectiveness, as applicable, of the Plan,
if so requested by TWNY, if the failure to so waive such condition(s) would
reasonably be expected to materially delay or impair the Transaction. Adelphia
hereby acknowledges and agrees that with respect to the conditions set forth in
Sections 13.01(a), 13.01(b) and 13.01(c) of the Plan, if so requested by TWNY,
it will exercise its discretion in a reasonable manner. The foregoing shall not
prejudice either party's position with respect to Adelphia's waiver obligations,
if any, in respect of any provision of Sections 13.01 and 13.02 of the Plan that
is not addressed in this paragraph.

      4. Reservation of Rights. It is understood and agreed that the filing of
the Plan and TWNY's consent thereto are without prejudice to Adelphia's rights
to amend the Plan and TWNY's right to consent or to withhold consent to any
amendment (and the absence or presence of any provision of the Plan as filed
shall not be taken into account in determining such rights of Adelphia or TWNY),
in each case, in accordance with applicable provisions of the TW Purchase
Agreement.

      5. Issuance of Parent Capital Stock. TWNY acknowledges that in connection
with the Transaction it currently intends to cause Parent to effect a stock
dividend and distribute approximately 999,999 shares of Parent Capital Stock in
respect of each share of Parent Capital Stock outstanding as of the record date
for such dividend. TWNY further acknowledges and agrees that in the event that
the number of shares of Parent Capital Stock to be issued at the Closing is
changed it shall use its commercially reasonable efforts to cause the initial
pricing of such shares to be in a reasonable range in light of the current
intended share price and then prevailing market conditions.

         This letter agreement may be executed in one or more counterparts, each
of which shall be deemed an original, and all of which shall constitute one and
the same letter agreement.

         This letter agreement shall be governed by and construed in accordance
with the TW Purchase Agreement.

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      Please confirm your agreement with the foregoing by signing and returning
a copy of this agreement to the undersigned.

                                            Very truly yours,

                                            TIME WARNER NY CABLE LLC

                                            By: /s/ Satish R. Adige
                                               ---------------------------------
                                               Name: Satish R. Adige
                                               Title: Sr. V.P., Investments

Agreed and Acknowledged:

ADELPHIA COMMUNICATIONS CORPORATION

By: /s/ Brad M. Sonnenberg
    ----------------------------------------
    Name: Brad Sonnenberg
    Title: Executive Vice President, General Counsel and Secretary

Acknowledged and approved:

COMCAST CORPORATION

By: /s/ Robert S. Pick
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    Name: Robert S. Pick
    Title: Senior Vice President