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                                                                   EXHIBIT 10.27


                            FORM OF PROMISSORY NOTE

$50,000,000.00                                                ____________, 2000


         FOR VALUE RECEIVED, PATHNET TELECOMMUNICATIONS, INC., a corporation
duly organized under the laws of the State of Delaware (the "Borrower"),
promises to pay to Pathnet, Inc., a Delaware corporation, at 1015 31st Street,
N.W., Washington, DC 20007 (the "Lender"), or at such other place as the holder
of this Note may from time to time designate in writing, the principal amount of
FIFTY MILLION AND NO/100 DOLLARS ($50,000,000.00), together with interest on the
unpaid principal amount of this Note computed from the date of Closing as
defined in that certain Assignment and Acceptance Agreement by and between
Borrower and Lender, dated the date hereof, as amended from time to time, until
the entire indebtedness is paid, at the rate of twelve and one quarter percent
(12-1/4%) per annum. The principal amount of this Note shall be due and payable
on March 31, 2010. Accrued interest calculated on the outstanding principal
amount as described above shall be payable yearly on the last day of each year
commencing with the year ended December 31, 2000. All payments hereunder shall
be made in lawful money of the United States of America.

         This Note may be prepaid at any time and from time to time, in whole or
in part, without premium or penalty. Any prepayment shall be applied first to
any accrued and unpaid interest and then to principal. In the event of
prepayment of this Note in part only, a new Note for the unpaid portion hereof
shall be issued in the name of the person or entity in whose name this Note is
registered upon the cancellation hereof.

         The entire unpaid principal amount of this Note or any extension or
renewal hereof, together with accrued interest and all charges owing under this
Note, shall immediately become due and payable at the option of the holder of
this Note, without demand or notice, upon the occurrence of any of the following
Events of Default:

         (a) Borrower fails to pay the principal amount of this Note when the
same becomes due and payable (whether on the date on which such principal
becomes due or upon acceleration or otherwise); or

         (b) Borrower fails to pay any interest when the same becomes due and
payable hereunder and such failure to pay continues for ten (10) business days
after the date on which such payment of interest was due.

         If this Note, after maturity, whether by acceleration or otherwise, is
placed in the hands of an attorney for collection, whether suit is brought on
the same or not, Borrower shall pay to the holder of this Note all attorneys'
fees as are incurred for the purposes of collection hereof.

         Each Obligor under this Note (which term shall include all makers,
guarantors, endorsers and other persons assuming obligations pursuant to this
Note) hereby waives presentment, protest, demand, notice of dishonor, and all
other notices, and all defenses
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and pleas on the grounds of any extensions of the time of payments or the due
dates of this Note, in whole or in part, before or after maturity, with or
without notice. No renewal or extension of this Note, no release or surrender of
any collateral given as security for this Note, no release of any Obligor, and
no delay in enforcement of this Note or in exercising any right or power
hereunder, shall affect the liability of any Obligor.

         This Note may not be changed orally, but only by an agreement in
writing which is signed by the party against whom enforcement of any waiver,
change, modification or discharge is sought. This Note is made under, and shall
be governed by and construed in accordance with, the laws of the State of New
York applicable to contracts made and to be performed entirely within such State
and without giving effect to choice of law principles of such State.

         IN WITNESS WHEREOF, Borrower has caused this Note to be duly executed
on its behalf as of the date set forth at the beginning of this Note, as the act
and deed of Borrower.


                                    PATHNET TELECOMMUNICATIONS, INC.


                                    By: ______________________________________
                                        Name:
                                        Title:


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