January 19, 2011

Carl Grivner
Chief Executive Officer
XO Holdings, Inc.
13865 Sunrise Valley Drive
Herndon, VA 20171

Dear Carl:

Carl  C.  Icahn, the Chairman of XO Holdings, Inc. (the "Company"), beneficially
owns  a  majority  of  the outstanding shares of the Company's common stock (the
"Common  Stock")  through  ACF  Industries  Holding  Corp.  ("ACF Holding"). ACF
Holding  is  interested  in  acquiring, either directly or through an affiliate,
ownership of 100% of the Company, in a transaction the exact form of which would
be  determined  jointly.  Under  this  proposal,  holders of Common Stock of the
Company,  other than ACF Holding and its affiliates, would receive consideration
of  $.70  net  per  share  in  cash.

This  proposed  transaction  would  not  be subject to the acquirer's ability to
obtain  financing  or to the results of any due diligence review of the Company.

Accordingly,  ACF  Holding  hereby  requests  that  you initiate the appropriate
process  so  that  the  Company  can  commence  reviewing  and  considering this
proposal. We request the opportunity to have representatives of ACF Holding meet
with  those  persons  who  would  be  considering  the  proposal for the Company
together with the advisors to such persons to engage in a dialogue about why ACF
Holding believes that the proposed $.70, price net per share in cash, represents
appropriate  consideration  to  be  paid  to  the  minority  stockholders.

In connection with the foregoing, please note that in no event is ACF Holding or
its  affiliates  prepared  to  be  a seller of its shares of Common Stock in any
transaction  and  therefore  it  will not sell or transfer its shares to a third
party  or  vote in favor of a transaction which involves the sale or transfer of
its  shares  to  a  third  party.

This letter shall not constitute a binding agreement between us and no agreement
shall  exist  between  us regarding the foregoing unless and until we enter into
mutually  satisfactory  definitive agreements. Please do not hesitate to contact
the  undersigned  at  212-702-4300  with  any  questions  or  comments.


                                              Very truly yours,

                                              ACF INDUSTRIES HOLDING CORP.


                                              By:  /s/ Keith Cozza
                                                   ----------------
                                                   Keith Cozza, Vice President