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                                                                  EXHIBIT 10.50
                                                                  5/14/97 TCOMA
                             AMENDMENT TO AGREEMENT

                  This Amendment to Agreement is made as of the 1st day of
March, 1999, and amends the Non-Qualified Stock Option and Stock Appreciation
Rights Agreement, dated as of May 14, 1997 (the "Agreement"), pertaining to
shares of TCI Group Series A Common Stock ("TCOMA") by and between
Tele-Communications, Inc. a Delaware corporation (the "Company") and the person
to whom such options were granted as provided in the Agreement (the "Grantee").
All terms used in this Amendment shall have the meanings set forth in the
Agreement except where specifically set forth herein.

                  This Amendment is made pursuant to paragraph 15(a) of the
Agreement which permits the Agreement to be amended to add to the agreements of
the Company for the benefit of the Grantee, provided that such amendment shall
not adversely affect the rights of the Grantee with respect to the Award
evidenced by the Agreement. It has been determined by the Committee that this
Amendment does not adversely affect the rights of the Grantee with respect to
the Award evidenced by the Agreement.

                  Pursuant to the Plan, the Compensation Committee of the Board
has determined that, pursuant to paragraph 15a(ii) of the Agreement:

                  1. Paragraph 4 of the Agreement shall be amended by deleting
the last full paragraph therein in its entirety and deleting the last sentence
of Paragraph 4(a) and replacing such sentence with the following language:

                  Notwithstanding the foregoing, all TCOMA Option Shares shall
                  become available for purchase if Grantee's employment with
                  the Company and its Subsidiaries (i) shall terminate by
                  reason of (x) termination by the Company without cause (as
                  defined in Section 11.2(b) of the Plan), (y) termination by
                  Grantee for good reason (as defined herein) or (z)
                  Disability, (ii) shall terminate pursuant to provisions of a
                  written employment agreement, if any, between the Grantee and
                  the Company which expressly permit the Grantee to terminate
                  such employment upon the occurrence of specified events
                  (other than the giving of notice and passage of time), or
                  (iii) if Grantee dies while employed by the Company or a
                  Subsidiary.

                  2. Paragraph 8 of the Agreement shall be amended to read in
its entirety as follows:

                           8. EARLY TERMINATION OF OPTION AND TANDEM SARS.
                  Unless otherwise determined by the Committee in its sole
                  discretion, the TCOMA Option and TCOMA Tandem SARs shall
                  terminate, prior to the expiration of the TCOMA Option Term,
                  at the time specified below:

                           (a) If Grantee's employment with the Company and its
                  Subsidiaries terminates (i) other than (x) by the Company for
                  "cause" (as defined in Section 11.2(b) of the Plan), (y) by
                  the Grantee with "good reason" (as defined herein) or (z) by
                  the Company without cause, 






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                  and (ii) other than (x) by reason of death or Disability, (y)
                  with the written consent of the Company or the applicable
                  Subsidiary or (z) without such consent if such termination is
                  pursuant to provisions of a written employment agreement, if
                  any, between the Grantee and the Company which expressly
                  permit the Grantee to terminate such employment upon the
                  occurrence of specified events (other than the giving of
                  notice and passage of time), then the TCOMA Option and all
                  TCOMA Tandem SARs shall terminate at the Close of Business on
                  the first business day following the expiration of the 90-day
                  period which began on the date of termination of Grantee's
                  employment;

                           (b) If Grantee dies while employed by the Company or
                  a Subsidiary, or prior to the expiration of a period of time
                  following termination of Grantee's employment during which
                  the TCOMA Option and TCOMA Tandem SARs remain exercisable as
                  provided in paragraph (a), the TCOMA Option and all TCOMA
                  Tandem SARs shall terminate at the Close of Business on the
                  first business day following the expiration of the one-year
                  period which began on the date of death;

                           (c) If Grantee's employment with the Company and its
                  Subsidiaries terminates by reason of Disability, then the
                  TCOMA Option and all TCOMA Tandem SARs shall terminate at the
                  Close of Business on the first business day following the
                  expiration of the one-year period which began on the date of
                  termination of Grantee's employment;

                           (d) If Grantee's employment with the Company and its
                  Subsidiaries is terminated by the Company for "cause" (as
                  defined in Section 11.2(b) of the Plan), then the TCOMA
                  Option and all TCOMA Tandem SARs shall terminate immediately
                  upon such termination of Grantee's employment; or

                           (e) If Grantee's employment (i) is terminated by
                  Grantee (x) with "good reason" (as defined herein), (y) with
                  the written consent of the Company or the applicable
                  Subsidiary or (z) pursuant to provisions of a written
                  employment agreement, if any, between the Grantee and the
                  Company which expressly permit the Grantee to terminate such
                  employment upon the occurrence of specified events (other
                  than the giving of notice and passage of time), or (ii) by
                  the Company without "cause" (as defined in Section 11.2(b) of
                  the Plan), then the TCOMA Option Term shall terminate early
                  only as provided for in paragraph 8(b) above or 12(b) below.

                                    In any event in which the TCOMA Option and
                  TCOMA Tandem SARs remain exercisable for a period of time
                  following the date of termination of Grantee's employment as
                  provided above, the TCOMA Option and TCOMA Tandem SARs may be
                  exercised during such period of time only to the extent the
                  same were exercisable as provided in paragraph 4 above on
                  such date of termination of Grantee's employment. A change of
                  employment is not a termination of employment within the
                  meaning of this paragraph 8 provided that, after giving
                  effect to such change, the Grantee continues to be an
                  employee of the Company or any Subsidiary. Notwithstanding
                  any period of time referenced in this paragraph 8 or any
                  other provision of this paragraph that may be construed to
                  the contrary, the TCOMA Option and all TCOMA Tandem SARs
                  shall in any event terminate upon the expiration of the
                  Option Term.


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                                    "Good reason" for purposes of the Agreement
                  shall be deemed to have occurred upon the happening of any of
                  the following:

                           (i) any reduction in Grantee's annual rate of salary;

                           (ii) either (x) a failure of the Company to continue
                  in effect any employee benefit plan in which Grantee was
                  participating or (y) the taking of any action by the Company
                  that would adversely affect Grantee's participation in, or
                  materially reduce Grantee's benefits under, any such employee
                  benefit plan, unless such failure or such taking of any
                  action, adversely affects the senior members of the corporate
                  management of the Company generally;

                           (iii) the assignment to Grantee of duties and
                  responsibilities that are materially more oppressive or
                  onerous than those attendant to Grantee's position
                  immediately after the date hereof;

                           (iv) the relocation of the office location as
                  assigned to Grantee by the Company to a location more than 20
                  miles from Grantee's then current location without Grantee's
                  consent; or

                           (v) the failure of the Company to obtain, prior to
                  the time of any reorganization, merger, consolidation,
                  disposition of all or substantially all of the assets of the
                  Company or similar transaction effective after the date
                  hereof, in which the Company is not the surviving person, the
                  unconditional assumption in writing or by operation of law of
                  the Company's obligations to Grantee under this Agreement by
                  each direct successor to the Company in any such transaction.

                  All other terms of the Agreement shall remain the same.

                                          TELE-COMMUNICATIONS, INC.



                                          By:
                                             ----------------------------------
                                               Stephen M. Brett
                                               Executive Vice President,
                                               Secretary and General Counsel