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                                                                    EXHIBIT 10.1

                    AGREEMENT REGARDING CERTAIN COMPENSATION

                  This AGREEMENT REGARDING CERTAIN COMPENSATION, dated and
effective (except as otherwise set forth herein) this 23rd day of June, 2001
(the "Effective Date"), is made by and between Global TeleSystems, Inc., a
Delaware corporation (the "Company"), and Robert J. Amman (the "Executive" and
collectively, the "Parties").

                  WHEREAS, the Executive has heretofore been employed by the
Company pursuant to (i) that certain Amended and Restated Employment Agreement
dated and effective November 1, 2000 (the "Employment Agreement") which sets
forth certain terms and conditions with respect to the Executive's employment
with the Company, and which is attached hereto as Exhibit A and (ii) that
certain letter agreement (the "Letter Agreement") which sets forth certain terms
and conditions with respect to that certain Performance Bonus payable to the
Executive by the Company (the "Performance Bonus"), and which is attached hereto
as Exhibit B; and

                  WHEREAS Executive has in good faith fully performed all his
duties and responsibilities to the Company pursuant to the Employment and Letter
Agreements by, for example, obtaining for the Company approximately 85% of the
economic value sought to be obtained through, inter alia, the Letter Agreement;
and

                  WHEREAS, Executive has unique experience and expertise in
financial restructuring of the kind in which the Company is currently engaged
and it is the desire of the Company to assure itself of continuous access to
Executive's services; and

                  WHEREAS, it can be presumed that the Executive has available
to him numerous alternative sources of employment; and

                  WHEREAS, due to the Company's changed economic and financial
circumstances and strategies, it is likely that the compensation packages and
retention incentives set forth in the Employment Agreement and the Letter
Agreement no longer provide appropriate incentives to the Executive to perform
and to remain in the employ of the Company; and

                  WHEREAS, the Parties have agreed that it is in their mutual
best interest to amend the Employment Agreement to increase the Executive's
salary and to provide the Executive with certain other retention and incentive
payments in lieu of certain severance programs now set forth therein; and

                  WHEREAS, the Parties have agreed that it is in their mutual
best interest that the Company pay a portion of the Performance Bonus in lieu of
other payments possibly called for under the Letter Agreement and to terminate
the Letter Agreement and Executive's right to further payments of the
Performance Bonus thereunder;

                  NOW THEREFORE, in consideration of the foregoing and other
good and valuable consideration, the receipt and sufficiency of which is hereby
acknowledged by the Parties, the Parties do hereby agree as follows:


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         A. FIRST AMENDMENT TO AMENDED AND RESTATED EMPLOYMENT AGREEMENT. The
Employment Agreement is hereby amended, effective as of the Effective Date, as
follows:

             1. Annual Base Salary. Section 5(a) of the Employment Agreement is
         hereby amended as follows:

                a. The first sentence of Section 5(a) is hereby deleted in its
              entirety and replaced with the following sentence: "During the
              Term, Executive shall receive a base salary at a rate of not less
              than $600,000 per annum, which shall be increased to $1,500,000
              per annum as of July 1, 2001 (the "Annual Base Salary"), less
              standard deductions, paid in accordance with the Company's general
              payroll practices for executives, but no less frequently than
              monthly."

                b. The following sentence is hereby added to the end of Section
              5(a): "The Executive agrees that, in partial consideration for the
              increase in his Annual Base Salary to $1,500,000 described above,
              he shall not, except in extraordinary circumstances approved by
              the Board, be entitled to receive any bonus payments pursuant to
              Section 5(b) hereof on or after July 1, 2001."

             2. Special Retention Bonus. A new Section 5(i) shall be added to
         the Employment Agreement to read as follows:

                           "(i) Special Retention Bonus. On July 1, 2001 (or
                  within a reasonable time thereafter), the Company shall pay to
                  the Executive a retention bonus in the amount of $2,500,000
                  (the "Special Retention Bonus"), provided, however, that in
                  the event the Executive's employment with the Company
                  terminates under circumstances other than (a) the Executive's
                  termination by the Company without Cause; (b) the Executive's
                  death or Disability or (c) the Executive's resignation for
                  Good Reason, the Executive shall pay to the Company, in cash,
                  (x) within ten days of such termination, an amount equal to
                  the Special Retention Bonus less any taxes paid by or on
                  behalf of Executive based upon or due to his receipt of such
                  Special Retention Bonus and (y) within ten days of Executive's
                  receipt thereof, an amount equal to the amount of any tax
                  refund, credit or other tax benefit received or recognized by
                  the Executive pursuant to his previous compliance under
                  Section 5(i)(x) or (y) hereof Provided that, if the Company
                  shall have withheld portions of the Special Retention Bonus
                  for tax payments and such Special Retention Bonuses shall have
                  to be repaid by Executive under the terms hereof, or for any
                  other reason, the amount of such withholding shall be deemed
                  repaid by the Executive at the same time Executive repays the
                  net amount of the Special Retention Bonus actually paid to
                  him."

             3. Certain Amendments to Severance Arrangements. In partial
         consideration for the awarding and payment of the Special Retention
         Bonus described in Section 2 of this agreement, Executive agrees to
         waive his right to the severance payments set forth and described in
         Section 7(a)(i)(B) of the Employment Agreement (but, for clarity, other
         severance benefits set forth in the Employment Agreement will continue
         to be due and paid to Executive under their terms) and Section
         7(a)(i)(B) of


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         the Employment Agreement shall be deleted in its entirety and replaced
         with the phrase "Intentionally Deleted".

             4. Special Restructuring Success Bonus. A new Section 5(j) shall be
         added to the Employment Agreement to read as follows:

                           "(j) Special Restructuring Success Bonus. The Company
                  shall pay to the Executive a bonus in the amount of $2,500,000
                  (the "Special Restructuring Success Bonus") in payments as set
                  forth below, provided that (i) Executive is employed hereunder
                  on the date that the payment in question becomes due; or (ii)
                  if he is not employed hereunder at that time, his employment
                  had been previously terminated either (x) by the Company
                  without Cause; (y) by the Executive for Good Reason; or (z)
                  due to Executive's death that occurred within one year prior
                  to the date that such payment become due under the terms
                  hereof:

                                    (A) Restructuring -- In the event of a
                           contemplated restructuring (a "Restructuring") of the
                           balance sheet of the Company and Global TeleSystems
                           Europe B.V. (collectively, the "Companies") pursuant
                           to consensual written agreements (the "Restructuring
                           Agreements") between the Companies on the one hand
                           and formal or informal committees representing the
                           holders of publicly-traded debt, common stock and/or
                           preferred shares of or issued by the Companies (the
                           "Committees") on the other hand:

                                                   (x) 50% of the Special
                                          Restructuring Success Bonus shall vest
                                          and be payable upon the execution of
                                          the Restructuring Agreements, and

                                                   (y) the remainder of the
                                          Special Restructuring Success Bonus
                                          shall vest and be payable upon the
                                          earlier of (a) the issuance of any
                                          court orders required in the
                                          Restructuring Agreements as a
                                          condition for the effectiveness
                                          thereof, or, (b) if no such court
                                          orders are required in the
                                          Restructuring Agreements, upon
                                          execution of the Restructuring
                                          Agreements.

                                    (B) Sale of the Company - In the event of
                           the sale of all or substantially all of the equity in
                           or assets of either of the Companies that is approved
                           by the relevant Company's governing Board, (a
                           "Sale"):

                                                   (x) 50% of the Special
                                          Restructuring Bonus shall vest and be
                                          payable upon the signing of the
                                          definitive agreement for such Sale,
                                          and

                                                   (y) the remainder of the
                                          Special Restructuring Success Bonus
                                          shall vest and be payable upon the
                                          closing of such Sale."


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             5. Place of Performance. The first sentence of Section 4 of the
         Employment Agreement is hereby amended to read as follows:

                           "In connection with Executive's employment during the
                  Term, through June 30, 2001 Executive shall be based at the
                  Company's offices in London, England, except for necessary
                  travel on the Company's business and effective July 1, 2001
                  Executive shall be based at the Company's offices in
                  Arlington, Virginia or New York, New York (as the Executive
                  and the Company shall mutually agree), provided that Executive
                  is authorized to work from his home office in Atlanta, Georgia
                  and the Company shall reimburse his travel expenses to and
                  from Atlanta and from and to the Company office described
                  above, in accordance with its reimbursement practices for
                  senior executives."

         B. PAYMENT IN LIEU OF PERFORMANCE BONUSES. In full satisfaction of all
of its obligations under the Letter Agreement, and in recognition of his
assistance in achieving approximately 85% of the economic value sought to be
obtained through, inter alia, the letter agreement, the Company shall pay to the
Executive $1,275,000, which represents 85% of the total Performance Bonus, as
follows:

             1. $850,000 shall be payable upon the Effective Date (or as soon as
         reasonably practical thereafter); and

             2. $425,000 shall be payable upon completion or waiver of all of
         the transactions listed in Part II paragraphs 2.1 to 2.28 of the
         Explanatory Statement to the Scheme of Arrangement between Global
         TeleSystems (Europe) Limited and certain of its creditors (pursuant to
         section 425 of the Companies Act 1985).





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         IN WITNESS WHEREOF, the parties hereto have executed and delivered this
Agreement Regarding Certain Compensation as of the day and year first above
written.



                                       GLOBAL TELESYSTEMS, INC.



                                       By: /s/ ADAM SOLOMON
                                          --------------------------------------
                                       Name:  Adam Solomon
                                       Title: Chairman, Senior Executive
                                              Compensation Committee


EXECUTIVE:

/s/ ROBERT J. AMMAN
----------------------------------
Robert J. Amman
309 Blackland Road, N.W.
Atlanta, GA 30342