EXHIBIT 10.1


                      AMENDMENT TO NOTE PURCHASE AGREEMENT

     THIS  AMENDMENT  dated as of  February  12, 1999 (the  "AMENDMENT")  to the
separate  Note  Purchase  Agreements  dated as of December  28,  1995,  is among
Seitel,  Inc. (the "COMPANY") and each of the institutions  which is a signatory
to this Amendment (collectively, the "NOTEHOLDERS").

                                    RECITALS:

     A. The Company and each of the  Noteholders  have  heretofore  entered into
separate Note Purchase  Agreements dated as of December 28, 1995  (collectively,
as  in  effect   immediately  prior  to  this  Amendment,   the  "NOTE  PURCHASE
AGREEMENT").  The Company has  heretofore  issued  pursuant to the Note Purchase
Agreement:  (a)  $25,000,000  aggregate  principal  amount of its 7.17% Series A
Senior  Notes due  December  30, 2001 (the  "SERIES A NOTES"),  (b)  $27,500,000
aggregate  principal  amount of its 7.17% Series B Senior Notes due December 30,
2002 (the "SERIES B NOTES"),  and (c)  $22,500,000  of its Series C Senior Notes
due  December 30, 2002 (the  "SERIES C NOTES",  and  together  with the Series A
Notes and the Series B Notes, the "NOTES").  Capitalized terms used herein shall
have the respective  meanings  ascribed  thereto in the Note Purchase  Agreement
unless herein defined or the context shall otherwise require.

     B. The Company and the  Noteholders  now desire to amend the Note  Purchase
Agreement in the respects, but only in the respects, hereinafter set forth.

     C. All requirements of law have been fully complied with and all other acts
and  things  necessary  to make  this  Amendment  a  legal,  valid  and  binding
instrument  according to its terms for the purposes  herein  expressed have been
done or performed.

     NOW,  THEREFORE,  for good  and  valuable  consideration  the  receipt  and
sufficiency of which are hereby acknowledged, the Company and the Noteholders do
hereby agree as follows:

SECTION 1.     AMENDMENTS.

     1.1 Section  7.1(b) of the Note  Purchase  Agreement is hereby  amended and
restated in its entirety as follows:

          (B) ANNUAL STATEMENTS -- within ninety (90) days after the end of each
     fiscal year of the Company, duplicate copies of,

               (i)  a  consolidated   balance  sheet  of  the  Company  and  its
          consolidated Subsidiaries as at the end of such year,

               (ii) consolidated statements of operations,  stockholders' equity
          and cash flows of the Company and its  consolidated  Subsidiaries  for
          such year, and

               (iii) a condensed  consolidating  balance  sheet,  and  condensed
          consolidating  statements of operations  and cash flows of the Company
          and  its  Subsidiaries  setting  forth,  in each  case,  consolidating
          information  sufficient to show the financial  position and results of
          operations   and  cash  flows  of  the  Company  and  the   Restricted
          Subsidiaries,

     setting forth in each case in comparative form the figures for the previous
     fiscal year, all in reasonable  detail,  prepared in accordance  with GAAP,
     and accompanied by

                    (A) in the case of the  financial  statements  identified in
               the  foregoing  clauses  (i) and  (ii),  an  opinion  thereon  of
               independent  certified public accountants of recognized  national
               standing,   which  opinion   shall  state  that  such   financial
               statements  present  fairly,  in  all  material   respects,   the
               financial position of the companies being reported upon and their

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               results of  operations  and cash flows and have been  prepared in
               conformity   with  GAAP,   and  that  the   examination  of  such
               accountants in connection with such financial statements has been
               made in accordance with generally  accepted  auditing  standards,
               and that such audit provides a reasonable  basis for such opinion
               in the circumstances, and

                    (B) a certificate of such accountants stating that they have
               reviewed this Agreement and stating  further  whether,  in making
               their  audit,  they have become  aware of any  condition or event
               that then  constitutes a Default or an Event of Default,  and, if
               they are aware  that any such  condition  or event  then  exists,
               specifying  the nature and period of the  existence  thereof  (it
               being  understood  that such  accountants  shall  not be  liable,
               directly or  indirectly,  for any failure to obtain  knowledge of
               any Default or Event of Default  unless such  accountants  should
               have obtained  knowledge thereof in making an audit in accordance
               with generally  accepted auditing  standards or did not make such
               an audit),

     PROVIDED  that,  so long as the  Company  shall  not have any  Unrestricted
     Subsidiaries,  the delivery  within the time period  specified above of the
     Company's  Annual Report on Form 10-K for such fiscal year  (together  with
     the Company's annual report to shareholders,  if any,  prepared pursuant to
     Rule  14a-3  under  the  Exchange  Act)  prepared  in  accordance  with the
     requirements   therefor  and  filed  with  the   Securities   and  Exchange
     Commission,  together  with  the  accountants'  certificates  described  in
     clauses (A) and (B) above,  shall be deemed to satisfy the  requirements of
     this Section 7.1(b);

     1.2 Section  7.1(j) of the Note Purchase  Agreement  shall be relettered as
Section 7.1(k),  and a new Section 7.1(j) shall be inserted in its place to read
as follows:

          (J) AUDITED FINANCIAL  STATEMENTS FOR RESTRICTED GROUP -- with respect
     to any  fiscal  year of the  Company  as to  which  both  of the  following
     conditions would be satisfied:

               (i) the assets of all Unrestricted Subsidiaries,  determined on a
          combined  basis  as of the last day of such  year,  exceed  20% of the
          consolidated   total  assets  of  the  Company  and  its  consolidated
          Subsidiaries, and

               (ii) the revenues of all Unrestricted Subsidiaries, determined on
          a combined basis for such fiscal year,  exceed 20% of the consolidated
          revenues of the Company and its consolidated Subsidiaries,

     upon the written request of the Required Holders,  the Company will deliver
     to each  holder  that  is an  Institutional  Investor  the  same  financial
     statements  and opinion  with  respect to the  Company  and its  Restricted
     Subsidiaries  as is  provided  pursuant  to clauses (i) and (ii) of Section
     7.1(b) with respect to the Company and its consolidated  Subsidiaries (such
     delivery  to be made no later  than the later of (x) the time  delivery  is
     made of the  financial  statements  referred  to in such  clauses,  if such
     request is made at least 60 days  before  such  time,  or (y) 60 days after
     such request is made).

SECTION 2.     REPRESENTATIONS AND WARRANTIES OF THE COMPANY.

     To induce the  Noteholders  to execute and deliver  this  Amendment  (which
representations  shall  survive  such  execution  and  delivery),   the  Company
represents and warrants to the Noteholders that:

          (a) the Company is a corporation duly organized,  validly existing and
     in good standing under the laws of the state of Delaware;

          (b) this Amendment has been duly authorized, executed and delivered by
     the  Company  and this  Amendment  constitutes  a legal,  valid and binding
     obligation, contract and agreement of the Company enforceable against it in
     accordance  with  its  terms,  except  as  enforcement  may be  limited  by
     bankruptcy,  insolvency,  reorganization,  moratorium  or  similar  laws or
     equitable principles relating to or limiting creditors' rights generally;

          (c) the  Note  Purchase  Agreement,  as  amended  by  this  Amendment,
     constitutes the legal, valid and binding obligation, contract and agreement

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     of the Company  enforceable against it in accordance with its terms, except
     as enforcement  may be limited by bankruptcy,  insolvency,  reorganization,
     moratorium or similar laws or equitable  principles relating to or limiting
     creditors' rights generally;

          (d) the  execution,  delivery and  performance  by the Company of this
     Amendment (i) has been duly  authorized by all requisite  corporate  action
     and, if required,  shareholder action, (ii) does not require the consent or
     approval of any  governmental or regulatory body or agency,  and (iii) will
     not (A) violate (1) any  provision of law,  statute,  rule or regulation or
     its certificate of incorporation  or bylaws,  (2) any order of any court or
     any rule,  regulation  or order of any other agency or  government  binding
     upon it, or (3) any provision of any material indenture, agreement or other
     instrument to which it is a party or by which its  properties or assets are
     or may be bound, or (B) result in a breach of or constitute  (alone or with
     due  notice  or lapse  of time or  both) a  default  under  any  indenture,
     agreement or other  instrument  referred to in clause  (iii)(A)(3)  of this
     paragraph (c); and

          (e) as of the date hereof and after giving  effect to this  Amendment,
     no Default or Event of Default has occurred which is continuing.

SECTION 3.     MISCELLANEOUS.

     3.1 This Amendment shall be construed in connection with and as part of the
Note Purchase  Agreement,  and except as modified and expressly  amended by this
Amendment,  all terms,  conditions and covenants  contained in the Note Purchase
Agreement  and the Notes are  hereby  ratified  and shall be and  remain in full
force and effect.

     3.2 This  Amendment  constitutes  a contract  between  the  Company and the
Noteholders for the uses and purposes hereinabove set forth, and may be executed
in any  number  of  counterparts,  each  executed  counterpart  constituting  an
original, but all together only one agreement.

     3.3 Whenever any of the parties hereto is referred to, such reference shall
be deemed to include  the  successors  and  assigns of such  party,  and all the
promises  and  agreements  contained  in this  Amendment  by or on behalf of the
Company  and  the  Noteholders  shall  bind  and  inure  to the  benefit  of the
respective successors and assigns of such parties, whether so expressed or not.

     3.4 This Amendment  constitutes the final written  expression of all of the
terms hereof and is a complete and exclusive statement of those terms.

     3.5 This  Amendment  shall be governed by and construed in accordance  with
the law of the State of New York.

     3.6 This  Amendment  shall  become  effective  at such  time as it has been
executed by the Company and the Required Holders.

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     IN WITNESS  WHEREOF,  the parties  hereto have caused the execution of this
Amendment by duly authorized officers of each as of the date hereof.

                                            SEITEL, INC.

                                            By  /s/DEBRA D. VALICE
                                                --------------------------------
                                                Its  EXECUTIVE V.P. OF FINANCE
                                                --------------------------------

Accepted and Agreed to:

PRINCIPAL  LIFE  INSURANCE  COMPANY,
By Principal  Capital  Management,  LLC,
a Delaware limited liability company,
Its authorized signatory

By:  /s/JON C HEINY
     ---------------------------------------
Its: COUNSEL
     ---------------------------------------

By:  /s/RUSSELL S. ROWLEY
     ---------------------------------------
Its: INVESTMENT MANAGER
     ---------------------------------------

MASSACHUSETTS MUTUAL LIFE INSURANCE COMPANY

By:  /s/RICHARD C. MORRISON
     ---------------------------------------
     Name:    Richard C. Morrison
     Title:   Managing Director

FIRST SUNAMERICA LIFE INSURANCE COMPANY

By:  /s/CURT M. BURNS
     ---------------------------------------
     Name:  Curt M. Burns
     Title:   Authorized Agent

J. ROMEO & CO.

By:  /s/PETER COCCIA
     ---------------------------------------
     Name:    Peter Coccia
     Title:   Partner

UNITED OF OMAHA LIFE INSURANCE COMPANY

By:  /s/EDWIN H. HARRISON JR.
     ---------------------------------------
     Name:    Edwin H. Garrison Jr.
     Title:   First Vice President

PAN-AMERICAN LIFE INSURANCE COMPANY

By:  /s/F. ANDERSON STONE
     ---------------------------------------
     Name:    F. Anderson Stone
     Title:   Vice President
              Corporate Securities