Document:

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                                                                   Exhibit 10.18

                              EMPLOYMENT AGREEMENT
                              --------------------

     THIS AGREEMENT is entered into on September 1, 2000, by and between VIALOG
CORPORATION, a Massachusetts corporation (the "Company" or "VIALOG") and ROBERT
SAUR ("Mr. Saur").

                                     FACTS

     The Company desires to employ Mr. Saur as CHIEF INFORMATION OFFICER, with
the duties, responsibilities, rights and obligations set forth below, and Mr.
Saur desires to be so employed.

     In Mr. Saur's capacity as Chief Information Officer, he will obtain access
to, and be in a position to adversely affect, the confidential information and
good will of VIALOG and its subsidiaries (VIALOG and the subsidiaries
collectively and each individually referred to as the "VIALOG Group").

                                   AGREEMENT

     In consideration of the foregoing and of the covenants and agreements set
forth in this Agreement, the Company and Mr. Saur agree, as follows:

      1. Term. The term of this Agreement will commence as of October 18, 1999
         ----
(the "Effective Date"), and will continue from year-to-year thereafter, unless
terminated in accordance with the provisions of Section 6 of this Agreement or
not renewed in accordance with the provisions of Section 7 of this Agreement
(the "Term").

     2.  Duties and Responsibilities.
         ---------------------------

         (a) The Company agrees to employ Mr. Saur, and Mr. Saur agrees to be
     employed, as Chief Information Officer, and Mr. Saur will perform all of
     the duties and responsibilities of said office, subject to direction by the
     President and Chief Executive Officer of the Company. In addition, Mr. Saur
     will perform such other specific tasks and
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     responsibilities, consistent with his position as Chief Information
     Officer, as may be assigned to him from time to time by the President and
     Chief Executive Officer and the Board of Directors of the Company.

        (b)  The Company will have the right to reassign Mr. Saur to such other
     positions in the Company or within the VIALOG Group as the Company may
     determine, so long as such other positions involve a substantially similar
     level of compensation, authority and responsibility as the position of
     Chief Information Officer.  However, Mr. Saur will not be required to
     locate outside the Greater Boston metropolitan area, without his consent.

       (c) Mr. Saur will carry out his duties in a professional and competent
     manner and will devote his full business time, labor, skill and best
     efforts to carrying out his duties and responsibilities under this
     Agreement. Mr. Saur shall not engage in any other business activity during
     the term of this Agreement, except as may be approved by the Board of
     Directors.

       (d) Mr. Saur will travel to whatever extent may be reasonably necessary
     in the conduct of the VIALOG Group's business and his duties and
     responsibilities under this Agreement.

3.  Compensation.
    ------------

       (a) Subject to Mr. Saur's adherence to the responsibilities and
     obligations under this Agreement, the Company agrees to pay Mr. Saur a base
     compensation at the bi-weekly rate of Five Thousand Nine Hundred Sixty-One
     and 54/100 Dollars ($5,961.54), less all lawful holdings and deductions,
     which, if annualized, would equal One Hundred Fifty-Five Thousand Dollars
     ($155,000.00).

                                      -2-
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       (b) Mr. Saur will be eligible for such increases in base compensation and
     to participate in the Company's annual bonus compensation program, with a
     maximum potential annual pay-out of thirty percent (30%) of his base annual
     salary, as determined by the Board of Directors.

     4.  Benefits, Vacation and Stock Options.
         ------------------------------------

       (a) Mr. Saur will be eligible to participate in and/or receive such
     health, dental and other group benefit plans and vacation as the Company
     generally makes available to other employees on similar terms. The Company
     reserves the right to change or amend benefits at any time without prior
     notice.

       (b) The Company will purchase a term life insurance policy in the amount
     of One Million Dollars ($1,000,000.00) on Mr. Saur's behalf, and will pay
     the annual premium on such policy during the term of this Agreement.

       (c) Mr. Saur acknowledges that any and all benefits may be subject to
     state and/or federal taxation.

     5. Expense Reimbursement. Mr. Saur will be entitled to reimbursement for
        ---------------------
all reasonable and necessary business expenses properly incurred by him in
connection with the performance of his duties and responsibilities under this
Agreement, upon submission of documentation in accordance with such procedures
as the Company may establish from time to time.

     6. Termination. The Company may terminate Mr. Saur's employment at any time
        -----------
during the Term for any reason, as follows:

        (a) By the Company for Cause. The Company has the right to terminate Mr.
            ------------------------
     Saur's employment immediately for "Cause." For purposes of this Agreement
     only, the term "Cause" means: material breach of any provision of this
     Agreement; misconduct; nonperformance of Mr. Saur's duties or
     responsibilities; incompetence; inability to perform the essential
     functions of the office of Chief Information Officer,

                                      -3-
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     with or without reasonable accommodation as defined by the Americans With
     Disabilities Act ("ADA"); conviction of, or admission to, a felony or other
     crime involving moral turpitude; any act involving theft, embezzlement or
     fraud; or a material violation of any written policy of the Company. If Mr.
     Saur's employment is terminated for Cause, the Company will only be
     obligated to pay his base compensation through the date of such
     termination, together with such other benefits or payments to which Mr.
     Saur may be entitled (in the event of a Cause termination) by law or
     pursuant to benefit plans of the Company then in effect. Mr. Saur will
     remain bound by his obligations under Sections 8, 9 and 10 of this
     Agreement.

       (b) Death. In the event of Mr. Saur's death, the Company will pay to Mr.
           -----
     Saur's estate, designated beneficiary, or legal representative such base
     compensation and provide such comparable group health insurance benefits as
     Mr. Saur would have received (at such times as Mr. Saur would have received
     them) for a period equal to six (6) months after the date of death,
     together with such other benefits or payments to which Mr. Saur may be
     entitled by law or pursuant to benefit plans of the Company then in effect.
     For purposes of this Agreement, death shall terminate the Agreement.

       (c) Resignation and Termination Other than for Cause or Death. The
           ---------------------------------------------------------
     Company has the right to terminate Mr. Saur's employment other than for
     cause or death, without prior notice. Mr. Saur may terminate his employment
     upon thirty (30) days prior written notice to the Company. Mr. Saur will,
     in any event, remain bound by his obligations under Sections 8, 9 and 10 of
     this Agreement. If Mr. Saur's employment is terminated by Mr. Saur, he will
     not be entitled to any severance payments. If Mr. Saur's employment is
     terminated by the Company pursuant to this Section 6 (c), he will be
     entitled to a severance payment equal to six (6) months pay at his then
     current base rate of compensation, less all lawful withholdings and
     deductions, such severance payment to be paid in accordance with the
     regular pay periods of the Company.

     7. Renewal. This Agreement shall automatically renew year after year upon
        -------
the anniversary date of the Agreement, unless either party provides the other
with notice of its intent

                                      -4-
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not to renew the Agreement no less than ninety (90) days prior to the
anniversary date of the Agreement.

    8. Confidentiality. Mr. Saur will not at any time, without the Company's
       ---------------
prior written consent, reveal or disclose to any person outside of the VIALOG
Group, except in pursuit of the VIALOG Group's business, or use for his own
benefit or the benefit of any other person or entity, any confidential or
proprietary information concerning the business or affairs of the VIALOG Group,
or concerning the customers, clients or employees of the VIALOG Group
("Confidential and Proprietary Information"). For purposes of this Agreement,
Confidential and Proprietary Information includes, but is not limited to:
financial information or plans; sales and marketing information or plans;
business or strategic plans; salary, bonus or other personnel information of any
type; information concerning methods of operation; proprietary systems or
software; legal or regulatory information; cost and pricing information or
policies; information concerning new or potential products or markets; models,
practices, procedures, strategies or related information; research and/or
analysis; and information concerning new or potential investors, customers, or
clients. Confidential and Proprietary Information does not include information
already available to the public through no act of Mr. Saur, nor does it include
salary, bonus or other personnel information specific to Mr. Saur.

     Mr. Saur further understands and agrees that all Confidential and
Proprietary Information, however or whenever produced, will be the VIALOG
Group's sole property.  Upon the termination of Mr. Saur's employment, Mr. Saur
will promptly deliver to the Company all copies of all documents, equipment,
property or materials of any type in Mr. Saur's possession, custody or control
that belong to the VIALOG Group, and/or that contain, in whole or in part, any
Confidential or Proprietary Information.

     9.  Inventions.  During the Term of this Agreement, Mr. Saur will promptly
         ----------
disclose to the Company or any successor or assign, and grant to the Company and
its successors and assigns (without any separate remuneration or compensation
other than that received by Mr. Saur in the course of employment), Mr. Saur's
entire right, title and interest in and to any and all inventions, developments,
discoveries, models, or any other intellectual property of any type or

                                      -5-
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nature whatsoever ("Intellectual Property") developed during the Term of this
Agreement, whether developed by Mr. Saur during or after business hours, or
alone or in connection with others, reasonably related to the business of the
Company, the Subsidiaries and their respective successors or assigns, determined
as such business is constituted at the time of the invention. Mr. Saur agrees,
at the Company's expense, to take all steps necessary or proper to vest title to
all such Intellectual Property in the Company, its affiliates, successors,
assigns, nominees or designees, and to cooperate fully and assist the VIALOG
Group in any litigation or other proceedings involving any such Intellectual
Property.

     10. Restrictive Covenants. During the Restricted Period, as defined below,
         ---------------------
Mr. Saur will not, directly or indirectly, for his own account or for or on
behalf of any other person or entity, whether as an officer, director, employee,
partner, principal, joint venturer, consultant, investor, shareholder,
independent contractor or otherwise:

         (a) engage in any business in competition with the then business of the
     VIALOG Group, or in competition with any business that the VIALOG Group, to
     Mr. Saur's knowledge, actively was planning to enter at the time of the
     termination of Mr. Saur's employment;

         (b) solicit or accept business in competition with the VIALOG Group
     from any (i) clients of the VIALOG Group who were clients of the VIALOG
     Group at the time of the termination of Mr. Saur's employment, or who were
     clients during the two-year period preceding such termination, or (ii) any
     prospective clients of the VIALOG Group who, within two (2) years prior to
     such termination, had been solicited directly by Mr. Saur or where Mr. Saur
     supervised or participated in such solicitation activities;

         (c) hire or employ, or attempt to hire or employ, in any fashion
     (whether as an employee, independent contractor or otherwise), any employee
     or independent contractor of the VIALOG Group, or solicit or induce, or
     attempt to solicit or induce, any of the VIALOG Group's employees,
     consultants, clients, customers, vendors, suppliers, or independent
     contractors to terminate their relationship with the VIALOG Group; or

                                      -6-
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         (d) speak or act in any manner that is intended to, or does in fact,
     damage the goodwill or the business or reputation of the VIALOG Group.

     For purposes of this Agreement, the Restricted Period will be a period
beginning on the Effective Date and ending on the later of two (2) years after
(i) this Agreement terminates, or (ii) the end of the Severance Period.

     Mr. Saur may own not more than five percent (5%) of any class of securities
registered pursuant to the Securities Exchange Act of 1934, as amended, of any
corporation engaged in competition with the VIALOG Group, so long as Mr. Saur
does not otherwise (i) participate in the management or operation of any such
business, or (ii) violate any other provision of this Agreement.

     Mr. Saur understands and agrees that, by virtue of his position with the
Company, he will have substantial access to and impact on the good will,
confidential and proprietary information and other legitimate business interests
of the VIALOG Group, and therefore will be in a position to have a substantial
adverse impact on the VIALOG Group's business interests should he engage in
business in competition with the VIALOG Group.  Mr. Saur acknowledges that his
adherence to the restrictive covenants set forth in this Section is an important
and substantial part of the consideration that the Company is receiving under
this Agreement, and agrees that the restrictive covenants in this Section are
enforceable in all respects.  Mr. Saur consents to the entry of injunctive
relief to enforce such covenants, in addition to such other relief to which the
Company may be entitled by law, and he shall pay reasonable attorney's fees
incurred by the Company to enforce this Section of the Agreement.

     11. Specific Performance. Mr. Saur acknowledges that the VIALOG Group's
         --------------------
remedy at law for breach of Sections 8, 9 and 10 of this Agreement would be
inadequate, and agrees that, for breach of such provisions, the VIALOG Group is
entitled to injunctive relief and to enforce its rights by an action for
specific performance.

     12. Choice of Law. This Agreement, and all disputes arising under or
         -------------
related to it, will be governed by the law of the Commonwealth of Massachusetts.

                                      -7-
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     13. Choice of Forum. All disputes arising under or out of this Agreement
         ---------------
will be brought in courts of competent jurisdiction located within the
Commonwealth of Massachusetts.

     14. Assignment. This Agreement, and the rights and obligations of Mr. Saur
         ----------
and the Company, inures to the benefit of and is binding upon Mr. Saur, his
heirs and representatives, and upon the Company, the Subsidiaries and their
respective successors and assigns. This Agreement may not be assigned by Mr.
Saur. This Agreement may be assigned by the Company to any member of the VIALOG
Group.

     15. Notices. All notices required by this Agreement will be in writing and
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will be deemed to have been duly delivered when delivered in person, or when
mailed by certified mail, return receipt requested, or nationally recognized
next day delivery service, as follows:

          (a)  If to Mr. Saur, to the address which appears below Mr. Saur's
               signature to this Agreement; and

          (b)  If to the Company, to the following address:

               William Beaton, Vice President, Human Resources
               35 New England Business Center, Suite 160
               Andover, MA 01810

or to such other address as a party specifies in writing given in accordance
with this Section.

     16. Severability. If any one or more of the provisions of this Agreement is
         ------------
held to be invalid, illegal or unenforceable, the validity, legality and
enforceability of the remaining provisions will not in any way be affected or
impaired. Moreover, if any one or more of the provisions contained in this
Agreement is held to be excessively broad as to duration, activity or subject,
such provision will be construed by limiting or reducing it so as to be
enforceable to the maximum extent compatible with applicable law.

     17. Consultation with Counsel; No Representations. Mr. Saur acknowledges
         ---------------------------------------------
that he has had a full and complete opportunity to consult with counsel of his
own choosing concerning the terms, enforceability and implications of this
Agreement, and that the Company

                                      -8-
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has made no representations or warranties to Mr. Saur concerning the terms,
enforceability or implications of this Agreement other than are as reflected in
this Agreement.

     18.  Completeness of Agreement.  This Agreement contains all the terms and
          -------------------------
conditions agreed upon by the parties with reference to the subject matters
contained in this Agreement.  No other agreement, oral or otherwise, will be
deemed to exist or to bind either of the parties to this Agreement.  No
representative of any party to this Agreement had, or has, any authority to make
any representation or promise not contained in this Agreement, and each of the
parties to this Agreement acknowledges that such party has not executed this
Agreement in reliance upon any such representation or promise.  This Agreement
cannot be modified, except by a written instrument signed by both parties.

EMPLOYEE                          VIALOG CORPORATION

/s/ Robert Saur                   By:  /s/ Kim A. Mayyasi
-------------------------------      --------------------------------
Robert Saur                          Kim A. Mayyasi
                                     President and Chief Executive Officer

Address:

4 Mountain Home Road
Londonderry, NH 03053

Date:      September 1, 2000      Date:      September 21, 2000
     -------------------------          -----------------------------

                                      -9-MEMORANDUM OF AGREEMENT

                                     Between

                                 Tengasco, Inc.

                                       and

                           The University of Tennessee

              Concerning Cooperation on Matters Pertaining to the
                            Use of Seismic Equipment

PURPOSE

The purpose of this Agreement is to identify the roles and  responsibilities  of
Tengasco,  Inc.  (Tengasco),  a  publicly  held  company  with  headquarters  in
Knoxville, Tennessee, and The University of Tennessee in certain matters related
to  cooperative  use and  maintenance  of  seismic  equipment,  and to specify a
cost-effective  means of cooperation to enhance the  effectiveness of each party
in carrying out its mission.

BACKGROUND

The Department of Geological  Sciences at The University of Tennessee  possesses
certain  instruments,  vehicles,  and equipment that comprise a vibroseis system
for  producing  tomographic  images  of  subsurface  geologic  structures.   The
vibroseis  system can be used for  educational  and research  purposes  that are
beneficial to the University as an institution of research and higher  learning.
Tengasco is in the business of exploring  for and producing oil and natural gas,
and supplies natural gas to certain municipalities and businesses, in Tennessee.
Tengasco uses vibroseis imaging in the course of their business operations.

Central to a vibroseis system is the servo-hydraulic  vibrator, a truck-mounted,
hydraulically operated engine capable of applying approximately 14 tons of force
to the surface of the earth for the purpose of  generating  seismic  waves.  The
vibrator  requires specially trained operators and routine,  expert maintenance.
The University  possesses one model Y-1100A vibrator  manufactured by the George
E. Failing Company.  Tengasco owns two Y-1100A vibrators. The cost operating and
maintaining a vibroseis  system at The University for  educational  and research
purposes exceeds the resources  available at the  institution.  For this reason,
the vibroseis  system owned  by the University remained unused since about 1994.
The condition of the vehicles and other vibroseis equipment  deteriorates due to
inactivity and lack of routine maintenance.

GENERAL AGREEMENT

The parties agree on the following points:

<PAGE>

COOPERATION.  The University of Tennessee and Tengasco agree to cooperate in the
maintenance and operation of their vibroseis systems.

EQUIPMENT.  The Equipment covered by this Agreement includes the servo-hydraulic
vibrators,  together with the electronic controls,  radios,  geophones,  cables,
seismographs,  and  vehicles  used  to  produce  seismic  data at  remote  field
locations.  Not  included  under  this  Agreement  are  computers  or other data
processing equipment  permanently installed in laboratories at The University of
Tennessee.  Also not  included is  equipment  installed  as part of the regional
seismic   network  used  for  monitoring   earthquakes  in  East  Tennessee  and
surrounding areas.

OWNERSHIP.  The Equipment currently in possession of the University shall at all
times remain the property of The University of Tennessee. The Equipment owned by
Tengasco shall remain the sole property of Tengasco.

USE.  Tengasco shall have the right to use the Equipment as it deems appropriate
for its business objectives. The University of Tennessee shall have the right to
use the Equipment for educational and research projects.  When Tengasco uses the
Equipment,   the  persons  permitted  to  operate  the  equipment  will  include
employees,  contractors,  and agents of Tengasco.  When the University  uses the
Equipment,  the persons permitted to operate the Equipment will include faculty,
staff, and students at the University.

COSTS. The University and Tengasco  understand that use of the Equipment entails
costs to the owner for routine  maintenance  and operation.  Tengasco  agrees to
reimburse  The  University  for  all  regular  and  routine  maintenance  on the
Equipment  subject to this Agreement,  as required to keep the Equipment in good
operating  condition.  Tengasco  further  agrees to reimburse The University for
costs of  operation  when  Tengasco  employees,  contractors,  or agents use the
Equipment.  Tengasco  further  agrees  to an  additional  reimbursement  to  The
University  for  indirect  costs at the rate of 15% over and  above  the  direct
costs.

INDEMNIFY AND HOLD  HARMLESS.  Tengasco  agrees to indemnify  The  University of
Tennessee  from and against any claims or judgments  for damage to any person or
property arising out of the operation or maintenance of any Equipment subject to
this Agreement when operated by employees,  contractors,  or agents of Tengasco.
Tengasco agrees that its obligation to indemnify shall be supported by liability
insurance, naming The University of Tennessee as an additional insured, obtained
and maintained in force by Tengasco at its sole cost and expense.

NOT  EXCLUSIVE.  The parties  understand  and agree that this  Agreement  is not
exclusive. Other companies may enter into similar agreements to share equipment,
scientific  expertise,  or other  resources  with The  University  of Tennessee.
Tengasco  understands and acknowledges  that the University has an obligation to
cooperate with other agencies of the State or Federal government, and with other
companies  even if such  companies  may be in  competition  with Tengasco in the
business of oil and gas exploration. Other parties who may enter into agreements
with The University  should interpret  nothing in this Agreement to allow access
to Tengasco data or Equipment.

                                       2
<PAGE>

PROVISION OF SEISMIC INFORMATION AND DATA

The University of Tennessee  recognizes that the information  gathered by use of
the  Equipment  subject  to this  Agreement  and the  processed  results of that
information  is  or  may  be  of a  sensitive  and  proprietary  nature  to  the
exploration  business of Tengasco.  The University of Tennessee  agrees that any
information  obtained by Tengasco through use of the Equipment and the processed
results of that information  shall be held confidential and not disclosed to any
third  party  for a period  of one year  from the date any such  information  is
recorded  by  use of the  Equipment,  unless  required  to be  disclosed  by the
Tennessee Public Records Act, Tenn. Code Ann. ss. 10-7-503. Tengasco agrees that
use of this information by The University of Tennessee, its professors, students
or agents is not subject to this confidentiality requirement; provided, however,
that no  publication  of any  study  or  research  based  in whole or in part on
information  acquired by Tengasco  through  use of the  Equipment  shall be made
during the same one year period unless express written  permission is granted by
Tengasco.

IMPLEMENTING ARRANGEMENTS

The parties  agree to respect and  observe  the roles and  responsibilities  set
forth in this Agreement.

The Associate  Vice  President for Research for The  University of Tennessee and
the Chief  Executive  Officer for Tengasco are the  responsible  executives  for
implementing  this  Agreement.  If a disagreement  arises on the  implementation
requirements for this Agreement,  the issue will be submitted to the responsible
executives to this Agreement for adjudication.

In order to carry out the  Agreement,  separate  arrangements  will be  executed
between The University and Tengasco.  Those separate  arrangements  will provide
for, among other things, the statement of work and budget,  confidentiality  and
nondisclosure agreement, and will reference this Agreement.

Either party may terminate  this  agreement by providing  written  notice to the
other twelve months in advance of the effective date of termination.

For The University of Tennessee                 For Tengasco, Inc.

/s/ Kenneth R. Walker                           /s/ M. E. Ratliff
---------------------                           -----------------
Kenneth R. Walker                               M. E. Ratliff
Associate Vice President for Research           Chief Executive Officer
Date: 13 Feb. 01                                Date:
     --------------------------------                ---------------------------

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