Exhibit 10.12


                                LICENSE OF MARKS

                  WHEREAS,  Pathnet, Inc., a Delaware corporation having offices
at 1015 31st Street, N.W.,  Washington,  D.C., 20007 ("Licensor"),  has adopted,
used and is using certain trademarks, service marks, logos and designs including
without  limitation the "A NETWORK OF OPPORTUNITIES" and "PATHNET" service marks
and the Pathnet  logo (all such  trademarks,  service  marks,  logos and designs
shall be collectively referred to herein as the "Marks"); and

                  WHEREAS,   Pathnet   Telecommunications,   Inc.,   a  Delaware
corporation having offices at 1015 31st Street,  N.W.,  Washington,  D.C., 20007
("Licensee"), is desirous of a license to use the Marks;

                  NOW, THEREFORE,  for good and valuable consideration,  receipt
of which is hereby acknowledged, the parties hereto agree as follows:

1. LICENSE. Licensor does hereby grant to Licensee the perpetual,  non-exclusive
right and license to use the Marks on a  royalty-free  basis in connection  with
Licensee's  telecommunications  business; PROVIDED, HOWEVER, that Licensor shall
retain the right to use the Marks.

2. OWNERSHIP OF MARKS. Licensee acknowledges and agrees that (a) Licensor is the
owner of the entire right, title and interest in and to the Marks and the Marks,
or any form or  embodiment  thereof (as well as the  goodwill  now or  hereafter
attached to the same) are the property of and all use thereof shall inure to the
benefit of Licensor,  and (b)  Licensee  shall have no rights to the Marks other
than those set forth in this License of Marks.

3. APPROVALS/QUALITY  CONTROL.  Licensee shall, upon request of Licensor, submit
representative  samples  of  Licensee's  use of the Marks to  Licensor,  without
charge to Licensor,  and Licensor shall have a period of ten (10) days to notify
Licensee of their acceptance or rejection.

4.  REPRESENTATIONS,  WARRANTIES AND COVENANTS OF LICENSOR.  Licensor represents
and warrants that it is the owner of the Marks and the registrant therefor, that
Licensor has the full power and authority to license the right to use the Marks,
that Licensor has not entered into any  agreements in conflict with this License
of Marks,  and that there are no actions,  suits or  proceedings  pending or, to
Licensor's  knowledge,  threatened  against  Licensor with respect to the Marks.
Licensor  agrees to take all such  further  actions,  and to execute any and all
such  further  documents  and  instruments,  as may be necessary or desirable to
confirm the license executed hereby.

5. ASSIGNMENT. Neither party may assign any or all of its rights or delegate any
of its duties  under this  Agreement  without  the  consent of the other  party,
provided,  that  either  party  hereto  may  assign  its  rights,  but  not  its
obligations,  to any Affiliate  without the consent of the other party.  For the
purposes of this Section 5, an "Affiliate" of a party shall mean a subsidiary of
such party or other entity under common ownership or control.

                  IN  WITNESS  WHEREOF,  this  LICENSE  OF  MARKS  is  made  and
effective as of the 30th of March, 2000.



                                PATHNET, INC.

                                By: /s/ Mary McDermott
                                   -------------------------------------
                                Name: Mary McDermott
                                Title: Senior Vice President, General Counsel
                                        and Secretary


                                PATHNET TELECOMMUNICATIONS, INC.


                                By: /s/ Mary McDermott
                                   -------------------------------------
                                Name: Mary McDermott
                                Title: Senior Vice President, General Counsel
                                        and Secretary