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EXHIBIT 10.1

TAX SHARING AGREEMENT

by and among

AT&T CORP.,

LIBERTY MEDIA CORPORATION,
for itself and each member of the Liberty Group,

TELE-COMMUNICATIONS, INC.,

LIBERTY VENTURES GROUP LLC,

LIBERTY MEDIA GROUP LLC,

TCI STARZ, INC.,

TCI CT HOLDINGS, INC.

and

each Covered Entity listed on the signature pages hereof,

dated as of March 9, 1999

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TABLE OF CONTENTS

 
   
   
   
  Page  

1.

  Definitions     1  

2.

  Treatment of Legal Entities That Would be Members of Both Groups     6  

3.

  Tax Sharing Payments     7  

  (a)   Federal Income Taxes     7  

  (b)   Consolidated State, Local and Foreign Taxes     7  

  (c)   Certain Pre-Closing Taxes of the TCI Affiliated Group     8  

  (d)   Special Rules     9  

      (i)  

Certain Items for Liberty's Account

    9  

      (ii)  

Responsibility for DITS

    10  

      (iii)  

No Acceleration of DITS

    10  

      (iv)  

Accounts Under Old TCI Tax Sharing Agreements

    10  

      (v)  

Pre-Closing Losses; Pre-Closing Alternative Minimum Tax

    10  

      (vi)  

TCI Affiliated Group Non-NOL Carryover

    11  

      (vii)  

The Unused TCI Affiliated Group NOL

    11  

      (viii)  

Payment for NOL

    11  

      (ix)  

Post-Closing Compensation Deductions

    12  

      (x)  

Warrants

    12  

4.

  Subsidiary Payments     12  

5.

  Adjustments     12  

6.

  Separate Returns     13  

7.

  Interest on Unpaid Amounts     14  

8.

  Indemnification     14  

9.

  Liberty Contests and Filing of Returns     14  

10.

  Appointment of AT&T as Agent     16  

11.

  Cooperation     16  

12.

  Confidentiality     17  

13.

  Payment of Tax     17  

14.

  Calculation of Tax Sharing Payments and Resolution of Disputes     17  

15.

  Binding Effect; Successors and Assigns     17  

16.

  Interpretation     18  

17.

  Legal and Accounting Fees     18  

18.

  Effect of the Agreement     18  

19.

  Entire Agreement     18  

20.

  Code References     19  

21.

  Notices     19  

22.

  Counterparts     19  

23.

  New Members     20  

24.

  Nature of Obligations     20  

25.

  Termination     20  

26.

  Liberty Representation     20  

i

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TAX SHARING AGREEMENT

        TAX SHARING AGREEMENT (the "Agreement") entered into as of March 9,
1999, by and among AT&T Corp., a New York corporation ("AT&T"), Liberty Media
Corporation, a Delaware corporation ("Liberty"), for itself and on behalf of
each member of the Liberty Group (as defined below), Tele-Communications, Inc.,
a Delaware corporation ("TCI"), Liberty Ventures Group LLC, a Delaware limited
liability company, Liberty Media Group LLC, a Delaware limited liability company
("Liberty Group LLC"), TCI Starz, Inc., a Colorado corporation, TCI CT
Holdings, Inc., a Delaware corporation, each Covered Entity listed on the
signature pages hereof, and any entities which become parties hereto pursuant to
Section 23 hereof.

        WHEREAS, AT&T, Italy Merger Corp. ("Merger Sub") and TCI are parties to
an Agreement and Plan of Restructuring and Merger dated as of June 23, 1998 (the
"Merger Agreement") pursuant to which, among other things, subject to the terms
and conditions contained in the Merger Agreement, and concurrent with the
execution hereof, Merger Sub shall be merged with and into TCI with TCI
surviving as a wholly owned subsidiary of AT&T (the "Merger");

        WHEREAS Liberty desires to be included, and desires that the
Subsidiaries in the Liberty Group (as defined below) be included to the extent
permitted by applicable law, in the filing of consolidated federal income tax
returns on behalf of the AT&T Affiliated Group (as defined below);

        WHEREAS AT&T and Liberty wish to allocate and settle among themselves in
an equitable manner the consolidated federal income tax liability of the AT&T
Affiliated Group;

        WHEREAS Liberty desires, to the extent required or permitted by
applicable state, local or foreign law to be included, and that the Subsidiaries
in the Liberty Group be included, in combined, consolidated and unitary state,
local and foreign tax returns on behalf of the AT&T Affiliated Group; and

        WHEREAS AT&T and Liberty wish to allocate and settle among themselves in
an equitable manner the state, local or foreign tax liability in connection with
such combined, consolidated and unitary state, local and foreign income tax
returns;

        NOW, THEREFORE, in consideration of the mutual covenants contained
herein, the parties hereby amend and restate in its entirety the 1995 TCI Tax
Sharing Agreement and the 1997 TCI Tax Sharing Agreement (each as defined below)
and agree as follows:

        1.    Definitions.    Any terms used but not otherwise defined herein
shall have the meanings ascribed to such terms in the Merger Agreement. For
purposes of this Agreement, the following terms shall be defined as follows:

        (a)   "Advance" shall have the meaning set forth in Section 9(d).

        (b)   "Arbiter" shall have the meaning set forth in Section 3(d)(vii).

        (c)   "AT&T" shall have the meaning set forth in the first paragraph
hereof.

        (d)   "AT&T Affiliated Group" shall mean (i) the affiliated group,
within the meaning of Section 1504(a) of the Code, consisting of AT&T and
certain of its Subsidiaries, (ii) any combined,

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consolidated or unitary group for state, local or foreign Tax purposes that
files Joint Returns and (iii) any True Legal Entity that files Joint Returns.

        (e)   "AT&T Charter" shall mean the Certificate of Incorporation of
AT&T, as amended and in effect on the date hereof, after adoption of the AT&T
Charter Amendment (as defined in the Inter-Group Agreement).

        (f)    "AT&T Common Stock" shall have the meaning given to such term in
the Proxy Statement.

        (g)   "Code" shall mean the Internal Revenue Code of 1986, as amended.

        (h)   "Common Stock Group" shall mean AT&T, each of the other Legal
Entities that is or was at any time owned directly or indirectly by AT&T and any
Legal Entity tracked at any time by the TCI Group Tracking Stock; provided,
however, that the Common Stock Group shall not include any Legal Entity for such
period as and to the extent that such Legal Entity is a member of the Liberty
Group.

        (i)    "Common Stock Indemnitee" shall have the meaning set forth in
Section 8(a) hereof.

        (j)    "Consolidated Return Regulations" shall mean the Treasury
Regulations promulgated under Chapter 6 of Subtitle A of the Code, including, as
applicable, any predecessors or successors thereto.

        (k)   "Contested Liberty Group Item" shall have the meaning set forth in
Section 9(d).

        (l)    "Contribution Agreement" shall have the meaning ascribed to such
term in the Proxy Statement.

        (m)  "Corresponding Item" shall have the meaning set forth in the
definition of Timing Item.

        (n)   "Covered Entities" shall have the meaning ascribed to such term in
the Inter-Group Agreement.

        (o)   "Designated Rate" shall mean the underpayment rate applicable to
large corporate underpayments under the Code.

        (p)   "DIT" shall mean any "deferred intercompany transaction" or
"intercompany transaction" within the meaning of the Treasury Regulations (or
predecessors thereto).

        (q)   "Excess Basis" shall have the meaning set forth in Section 5(e).

        (r)   "Exhibit D DIT" shall mean any DIT listed on Exhibit D hereto.

        (s)   "Federal Tax Allocation Agreement" shall mean the Federal Tax
Allocation Agreement dated as of February 1, 1996 by and among AT&T and each of
its subsidiaries.

        (t)    "Final Determination" shall mean a closing agreement with the
Internal Revenue Service or the relevant state, local or foreign Taxing
authorities, an agreement contained in Internal Revenue Service Form 870AD or
other comparable form, an agreement that constitutes a determination under
Section 1313(a)(4) of the Code, a claim for refund which has been allowed, a
deficiency notice with respect to which the period for filing a petition with
the Tax Court or the relevant state, local or foreign tribunal has expired or a

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decision of any court of competent jurisdiction that is not subject to appeal or
as to which the time for appeal has expired.

        (u)   "GI" shall have the meaning ascribed to such term in the
Inter-Group Agreement.

        (v)   "Governmental Authority" shall have the meaning set forth in the
definition of "Tax."

        (w)  "Group" shall mean either the Common Stock Group or the Liberty
Group.

        (x)   "Hypothetical Legal Entity" shall have the meaning set forth in
Section 2.

        (y)   "Intercompany Account" shall have the meaning set forth in
Section 3(d)(iv).

        (z)   "Inter-Group Agreement" shall mean the Inter-Group Agreement by
and among AT&T, Liberty and others dated as of the date hereof.

        (aa) "Joint Return" shall mean any Tax Return that includes at least two
Legal Entities, of which one Legal Entity is a member of the Liberty Group and
the other Legal Entity is a member of (A) the TCI Group for taxable periods
ending on or prior to the Closing Date or (B) the Common Stock Group for taxable
periods ending after the Closing Date.

        (bb) "Legal Entity" shall mean a True Legal Entity or a Hypothetical
Legal Entity.

        (cc) "Letter Agreement" shall have the meaning set forth in
Section 3(d)(ii).

        (dd) "Liberty" shall have the meaning set forth in the first paragraph
hereof.

        (ee) "Liberty Group" shall mean the Legal Entities that own or owned the
assets, and are or were primarily responsible for the liabilities, tracked at
any time by the TCI Ventures Group Tracking Stock, the Liberty Media Group
Tracking Stock or the New Liberty Media Group Tracking Stock; provided, however,
that (x) the Liberty Group shall not include any such Legal Entity for such
period as and to the extent that the Legal Entity or its assets or liabilities
are tracked by the AT&T Common Stock or the TCI Group Tracking Stock, (y) except
for purposes of determining the amount of the Intercompany Account, the Liberty
Group shall not include for any period the Legal Entities listed on Exhibit A
hereto, and (z) the Liberty Group shall include the Legal Entities listed on
Exhibit B hereto beginning on the day following the Closing Date.

        (ff)  "Liberty Group LLC" shall mean Liberty Media Group LLC, a Delaware
limited liability company.

        (gg) "Liberty Indemnitee" shall have the meaning set forth in
Section 8(b) hereof.

        (hh) "Liberty Media Group Tracking Stock" shall have the meaning
ascribed to such term in the Proxy Statement.

        (ii)   "Liberty SRLY NOL" shall have the meaning set forth in
Section 3(d)(vii).

        (jj)   "Losses" shall mean costs, expenses, fees, liabilities,
obligations and losses.

        (kk) "Merger" shall have the meaning set forth in the recitals hereto.

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        (ll)   "Merger Agreement" shall have the meaning set forth in the
recitals hereto.

        (mm)  "Merger Sub" shall have the meaning set forth in the recitals
hereto.

        (nn) "New Liberty Media Group Tracking Stock" shall have the meaning
ascribed to such term in the Proxy Statement.

        (oo) "1995 TCI Tax Sharing Agreement" shall mean the Tax Sharing
Agreement dated as of July 1, 1995, as amended, by and among TCI, Liberty,
Tele-Communications International, Inc., TCI Technology Ventures, Inc., TCI
Communications, Inc. and TCI Cable Investments, Inc. and certain subsidiaries
thereof.

        (pp) "1997 TCI Tax Sharing Agreement" shall mean the Tax Sharing
Agreement dated as of October 1, 1997, as amended, by and among TCI, TCI
Communications, Inc., Liberty and TCI Ventures Group L.L.C. and certain
subsidiaries thereof.

        (qq) "Old TCI Tax Sharing Agreements" shall mean the 1995 TCI Tax
Sharing Agreement and the 1997 TCI Tax Sharing Agreement.

        (rr)  "Package Position" shall have the meaning set forth in
Section 9(c).

        (ss)  "Package Preparer" shall have the meaning set forth in
Section 9(c).

        (tt)  "Person" means any individual or corporation, company,
partnership, trust, incorporated or unincorporated association, joint venture or
other entity of any kind.

        (uu) "Phantom NOL" shall mean, in the case of any Redetermination, the
excess of the TCI Affiliated Group NOL determined without regard to such
Redetermination (but with regard to any prior Redeterminations) over the TCI
Affiliated Group NOL.

        (vv) "Pre-Closing Group" shall mean, for taxable periods ending on or
prior to the Closing Date, the Liberty Group or the TCI Group.

        (ww)  "Pre-Closing Taxable Period" for any Legal Entity shall mean any
taxabletaxable period that ends on or prior to the Closing Date with respect to
such entity.

        (xx) "Proxy Statement" shall mean the Proxy Statement/Prospectus of AT&T
and TCI dated January 8, 1999.

        (yy) "Reasonably Expected" shall have the meaning set forth in
Section 3(d)(vii).

        (zz) "Redetermination" shall mean any redetermination as the result of
an audit by the Internal Revenue Service (or the relevant state, local or
foreign Governmental Authority), a claim for refund, an amended Tax Return or
otherwise.

        (aaa)  "Separate Return" shall mean any Tax Return that is not a Joint
Return.

        (bbb)  "Settlement Advisor" shall have the meaning set forth in
Section 9(d).

        (ccc)  "Settlement Overpayment" shall have the meaning set forth in
Section 9(d).

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        (ddd)  "Sprint DIT" shall have the meaning set forth in
Section 3(d)(ii).

        (eee)  "State and Local Income Tax Allocation Agreement" shall mean the
State and Local Income Tax Allocation Agreement dated as of the first day of the
combined return Taxable year beginning January 1, 1995 by and among AT&T and
each of its subsidiaries.

        (fff) "Subsidiary" means, as to any Person, any other Person of which at
least (i) 50% of the equity and (ii) 50% of the voting interests are owned,
directly or indirectly, by such first Person.

        (ggg)  "Tax" shall mean any tax, wherever created or imposed, and
whether of the United States or elsewhere, and whether imposed by a local,
municipal, governmental, state, foreign, federation or other body (a
"Governmental Authority"), and, without limiting the generality of the
foregoing, shall include income, gross receipts, property, sales, use, license,
excise, franchise, employment, payroll, unemployment insurance, social security,
stamp, environmental, value added, alternative or added minimum, ad valorem,
trade, recording, withholding, occupation or transfer tax, custom or duty or
other like governmental assessment or charge of any kind whatsoever, together
with any related interest, penalties and additions imposed by any Governmental
Authority.

        (hhh)  "Tax Item" shall mean any item of income, gain, loss, deduction,
credit, recapture of credit or any other item which increases or decreases Taxes
paid or payable, including an adjustment under Code Section 481 resulting from a
change in accounting method.

        (iii)  "Tax Proceeding" shall mean any Tax audit, examination,
controversy or litigation.

        (jjj)  "Tax Return" shall mean any Tax report, return or other
information (including any attached schedules or any amendments to such report,
return or other information) required to be supplied to or filed with a
Governmental Authority, including an information return, claim for refund,
amended return or declaration or estimated Tax return.

        (kkk)  "Tentative Settlement Overpayment" shall have the meaning set
forth in Section 9(d).

        (lll)  "TCI" shall have the meaning set forth in the first paragraph
hereof.

        (mmm)  "TCI Affiliated Group" shall mean for taxable periods ending on
or prior to the Closing Date: (i) the affiliated group, within the meaning of
Section 1504(a) of the Code, consisting of TCI and certain of its Subsidiaries,
(ii) any combined, consolidated or unitary group, for state, local or foreign
Tax purposes that files Joint Returns that include solely members of the TCI
Group and the Liberty Group, and (iii) any True Legal Entity that files Joint
Returns that include solely members of the TCI Group and Liberty Group.

        (nnn)  "TCI Affiliated Group NOL" shall mean the unexpired regular Tax
net operating loss for federal income Tax purposes of the TCI Affiliated Group,
if any, as of the last day of the last taxable year ending on or prior to the
Closing Date, after giving effect to income, loss, audit adjustments, and the
effects of acts occurring in connection with the Merger Agreement.

        (ooo)  "TCI Affiliated Group Non-NOL Carryover" shall mean any
alternative minimum Tax credit carryover or other carryover of the TCI
Affiliated Group as of the last day of the last taxable year of the TCI
Affiliated Group ending on or prior to the Closing Date, after giving effect to
income, loss, audit adjustments and the effects of acts occurring in connection
with the Merger Agreement; provided, however, that the TCI Affiliated Group
Non-NOL Carryover shall not include (i) the TCI Affiliated Group NOL, (ii) any
foreign tax credit or charitable contribution carryovers allocable under the
Consolidated Return Regulations to

5

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Legal Entities in the Liberty Group and (iii) any net operating losses
reportable on a Separate Return of a Legal Entity in the Liberty Group.

        (ppp)  "TCI Group" shall mean such subset of the group of Legal Entities
that are members of the Common Stock Group as consists of TCI and each of the
Legal Entities that is or was at any time owned directly or indirectly by TCI
and owned or owns the assets and are or were primarily responsible for the
liabilities tracked by the TCI Group Tracking Stock; provided, however, that the
TCI Group shall not include any Legal Entity for such period as and to the
extent that such Legal Entity is a member of the Liberty Group.

        (qqq)  "TCI Group Tracking Stock" shall have the meaning given to such
term in the Proxy Statement.

        (rrr) "TCI Pre-AT&T Merger Restructuring Plan" shall mean the TCI
Pre-AT&T Merger Restructuring Plan that is attached hereto as Exhibit C.

        (sss) "TCI SRLY NOL" shall have the meaning set forth in
Section 3(d)(vii).

        (ttt) "TCI Ventures Group Tracking Stock" shall have the meaning
ascribed to such term in the Proxy Statement.

        (uuu)  "Tentative Settlement Overpayment" shall have the meaning set
forth in Section 9(d).

        (vvv)  "Timing Item" shall mean a Tax Item, the adjustment of which in
one taxable year results or may result in an increase in deduction, loss or
credit or a decrease in income, gain or recapture (a "Corresponding Item") in
another year.

        (www)  "Treasury Regulations" shall mean the Treasury Regulations
promulgated under the Code.

        (xxx)  "True Legal Entity" shall mean a corporation, partnership,
limited liability company or other legal entity under the corporation,
partnership, limited liability company or other organizational laws of a state
or other jurisdiction.

        (yyy)  "Unfiled Return" shall mean any Joint Return with respect to a
taxable period ending on or before the Closing Date that is not yet filed as of
the Closing Date.

        (zzz)  "Unpaid NOL" shall have the meaning given to such term in
Section 3(d).

        (aaaa)  "Unused TCI Affiliated Group NOL" shall mean the TCI Affiliated
Group NOL reduced by any portion thereof that has previously been used to
compute the reduction in the Liberty Group's payment obligations under
Section 3(d) or been used to compute AT&T's payment obligation to Liberty upon
deconsolidation under Section 3(d).

        (bbbb)  "Warrants" shall have the meaning ascribed to such term in the
Inter-Group Agreement.

        2.    Treatment of Legal Entities That Would be Members of Both
Groups.    In the event that a True Legal Entity owns assets or is primarily
responsible for liabilities tracked at once by both the TCI Group Tracking Stock
or AT&T Common Stock, on the one hand, and the TCI Ventures Group Tracking
Stock, Liberty Media Group Tracking Stock or New Liberty Media Group Tracking
Stock, on the other hand,

6

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each of the assets, liabilities and Tax attributes of the True Legal Entity
shall be treated at such time as divided between two hypothetical corporations,
partnerships, limited liability companies or other legal entities ("Hypothetical
Legal Entities"), each of which shall be treated at such time as owning the
assets, being primarily responsible for the liabilities, and having the Tax
attributes of, and Tax and legal personality comparable to those of, the True
Legal Entity associated with the business or investments of such Group. In the
event that a Tax attribute cannot be associated with the business or investments
of a single Group, it shall be reasonably allocated between the Hypothetical
Legal Entities taking into account the nature of the Tax attribute.

        3.    Tax Sharing Payments.    

        (a)   Federal Income Taxes.    With respect to consolidated federal
income Taxes, no later than five days prior to the due date (including
extensions) of any consolidated federal income Tax Return of the AT&T Affiliated
Group if such Tax Return is for a taxable period ending after the Closing Date:

          (i)  Liberty shall pay to AT&T the excess, if any, of (A) the sum of
(I) the aggregate amount of any Tax that would not have been incurred by the
AT&T Affiliated Group but for the inclusion of any Legal Entity that is a member
of the Liberty Group in the AT&T Affiliated Group and (II) the aggregate amount
of any Tax refund, credit or other Tax benefit that would have been realized or
received with respect to such Tax Return (or any other Tax Return that has been
or could have been filed) by the AT&T Affiliated Group but for the inclusion of
any Legal Entity that is a member of the Liberty Group in the AT&T Affiliated
Group over (B) the aggregate amount previously paid by Liberty pursuant to this
clause (i); and

         (ii)  AT&T shall pay Liberty the excess, if any, of (A) the sum of
(I) the aggregate amount of any Tax that would have been incurred by the AT&T
Affiliated Group but for the inclusion of any Legal Entity that is a member of
the Liberty Group in the AT&T Affiliated Group and (II) the aggregate amount of
any Tax refund, credit or other Tax benefit realized or received with respect to
such Tax Return that would not have been realized or received by the AT&T
Affiliated Group but for the inclusion of any Legal Entity that is a member of
the Liberty Group in the AT&T Affiliated Group over (B) the aggregate amount
previously paid by AT&T pursuant to this clause (ii);

provided, however, that the Consolidated Return Regulations and the consolidated
federal income Tax Returns filed by the AT&T Affiliated Group or the TCI
Affiliated Group pursuant to this Agreement or the Old TCI Tax Sharing
Agreements, respectively, shall determine the timing of the recognition of Tax
Items with respect to DITS and the determination of which Group (and which
member thereof) shall bear the Tax benefit or burden of such Tax Items, and each
Group shall be responsible for the Tax Items recognized by its respective
members with respect to any DITS; provided, further, however, that, solely for
purposes of determining the timing of the recognition of Tax Items resulting
from intercompany transactions for the "without" Liberty Group calculation, in
the case of any Tax Item of a member of the Common Stock Group arising from or
relating to any DIT in which a member of the Common Stock Group is the "seller"
and a member of the Liberty Group is the "buyer" (each within the meaning of the
Consolidated Return Regulations), until such time, if any, as the "buyer" is not
in fact a member of the AT&T Affiliated Group, the amounts referred to in
Sections 3(a)(i)(A) and 3(a)(ii)(A) shall be calculated by treating the buyer as
if it is a member of the AT&T Affiliated Group.

        (b)   Consolidated State, Local and Foreign Taxes.    With respect to
consolidated, combined, unitary or other Joint Return Taxes, other than
consolidated federal income Taxes, no later than five days prior to the due date
(including extensions) of any Joint Return of the AT&T Affiliated Group if such
Joint Return is for a taxable period ending after the Closing Date:

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          (i)  Liberty shall pay to AT&T the excess, if any, of (A) the sum of
(I) the aggregate amount of any Tax that would not have been incurred by the
AT&T Affiliated Group but for the inclusion of any Legal Entity that is a member
of the Liberty Group in the AT&T Affiliated Group and (II) the aggregate amount
of any Tax refund, credit or other Tax benefit that would have been realized or
received with respect to such Tax Return (or any other Tax Return that has been
or could have been filed) by the AT&T Affiliated Group but for the inclusion of
any Legal Entity that is a member of the Liberty Group in the AT&T Affiliated
Group over (B) the aggregate amount previously paid by Liberty pursuant to this
clause (i); and

         (ii)  AT&T shall pay Liberty the excess, if any, of (A) the sum of
(I) the aggregate amount of any Tax that would have been incurred by the AT&T
Affiliated Group but for the inclusion of any Legal Entity that is a member of
the Liberty Group in the AT&T Affiliated Group and (II) the aggregate amount of
any Tax refund, credit or other Tax benefit realized or received with respect to
such Tax Return that would not have been realized or received by the AT&T
Affiliated Group but for the inclusion of any Legal Entity that is a member of
the Liberty Group in the AT&T Affiliated Group over (B) the aggregate amount
previously paid by AT&T pursuant to this clause (ii);

provided, however, that (x) solely for purposes of determining the timing of the
recognition of Tax Items resulting from intercompany transactions for the
"without" Liberty Group calculation, in the case of any Tax Item of a member of
the Common Stock Group arising from or relating to any DIT in which a member of
the Common Stock Group is the "seller" and a member of the Liberty Group is the
"buyer" (each within the meaning of the Consolidated Return Regulations or
comparable provision of state, local or foreign law), until such time, if any,
as the "buyer" is not in fact a member of the AT&T Affiliated Group, the amounts
referred to in Sections 3(b)(i)(A) and 3(b)(ii)(A) shall be calculated by
treating the buyer as if it is a member of the AT&T Affiliated Group and for all
other purposes, the Consolidated Return Regulations (or comparable provisions of
state, local or foreign law) shall govern the timing of the recognition of Tax
Items for the members of the AT&T Affiliated Group and (y) all calculations
required to be made for purposes of clauses (b)(i) and (ii) above (including the
"without" Liberty Group calculations) shall be made using the apportionment
factors applicable to the Joint Return on a combined, consolidated or unitary
basis that includes all entities (including the members of the Liberty Group)
that are included in such Joint Return. In the case of any Joint Return of the
TCI Affiliated Group with respect to a taxable period that includes but does not
end on the Closing Date, such taxable period shall, for purposes of this
Agreement, be treated as consisting of one taxable period of the TCI Affiliated
Group ending on the Closing Date and another taxable period of the AT&T
Affiliated Group beginning on the day after the Closing Date, based on an
interim closing of the books as of the end of the day on the Closing Date.

        (c)   Certain Pre-Closing Taxes of the TCI Affiliated Group.

          (i)  In the case of any Unfiled Return of the TCI Affiliated Group for
consolidated federal income Taxes for any period ending on or prior to the
Closing Date, if such Tax Return as originally filed reflects a regular federal
income Tax liability, then Liberty shall pay AT&T the portion of such Tax
attributable to the Tax Items of the Liberty Group on a proportionate basis no
later than five days prior to the due date (including extensions) of such Tax
Return.

         (ii)  For each taxable period ending on or prior to the Closing Date,
the liability of each Pre-Closing Group with respect to unitary, consolidated,
nexus combination or other state or local income and franchise Taxes required to
be filed on Joint Returns shall be equal to the product of: (x) the sum of the
state and local income and franchise Taxes attributable to those jurisdictions
in which the TCI Affiliated Group is liable for state or local income or
franchise Taxes with respect to

8

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the operations of any Legal Entity that is a member of such Pre-Closing Group on
a unitary, consolidated, nexus combination or other Joint Return basis,
multiplied by (y) a fraction, (I) the numerator of which is the aggregate amount
of such Tax that is attributable to such Pre-Closing Group in such
jurisdictions, determined without regard to the other Pre-Closing Group, as
though such Pre-Closing Group were required to file either a unitary,
consolidated, nexus combination or other Joint Return corporate income or
franchise Tax Return (for this purpose, each limited liability company that is
wholly owned directly by TCI shall be treated as if it were a corporation) in
such jurisdictions for such taxable year or portion thereof, and (II) the
denominator of which is the sum of all such amounts determined with respect to
both Pre-Closing Groups. For each Tax Return that is the subject of this
Section 3(c)(ii), if a member of the Common Stock Group is required under the
law to file the applicable TCI Affiliated Group Joint Return, then Liberty shall
pay AT&T or TCI the amount for which the Liberty Group is responsible (based on
the fraction referred to in clause (y) above) with respect to such Tax Return no
later than five days prior to the due date (including extensions) of such Tax
Return, and if a member of the Liberty Group is required under the law to file
the applicable TCI Affiliated Group Joint Return, then AT&T or TCI shall pay
Liberty the amount for which the Common Stock Group is responsible (based on the
fraction referred to in clause (y) above) with respect to such Tax Return no
later than five days prior to the due date (including extensions) of such Tax
Return.

        (iii)  For each taxable period ending on or prior to the Closing Date,
the liability of each Pre-Closing Group with respect to foreign Taxes required
to be filed on Joint Returns shall be determined under the principles of
Section 3(c)(ii) above.

        (iv)  The Consolidated Return Regulations shall govern the timing of the
recognition of Tax Items of the members of the TCI Affiliated Group.

        (d)   Special Rules.    Notwithstanding any other provision of this
Agreement:

          (i)  Certain Items for Liberty's Account.    Any Tax Item arising from
or relating to (A) TCI Wireless Holdings Inc. or any of its direct or indirect
assets or subsidiaries, (B) the disposition of certain assets in exchange for
stock of GI or the subsequent disposition of such stock, or (C) except as
provided below in this Section 3(d)(i), the deemed, constructive or actual
disposition (except for the Exhibit D DITS) of the shares or other interests in
any Liberty Group Legal Entity, or measured by reference to the difference
between the value of such shares or interests and the holder's basis therein,
shall be for the account of the Liberty Group, and Liberty shall pay AT&T any
Tax (or any reduction in any Tax refund, credit or other benefit) attributable
thereto. AT&T and Liberty agree that any federal income Tax or Joint Return Tax
liability (including any reduction in the TCI Affiliated Group NOL) arising from
or relating to the federal income tax characterization or treatment of any class
of tracking stock of TCI or AT&T under the federal income tax law on the date
hereof will be equitably apportioned between the TCI Group or Common Stock
Group, on the one hand, and the Liberty Group, on the other hand. AT&T agrees
that (i) any Tax liability (or reduction in Tax benefit attributable to the
Liberty Group under this Agreement) that results from the breach of AT&T's
covenant in the Inter-Group Agreement that it will not issue any New Liberty
Media Group Tracking Stock after a Tax Law Change (as defined in the Inter-Group
Agreement), and (ii) any Tax liability (or reduction in Tax benefit attributable
to the Liberty Group under this Agreement) incurred as a result of the
settlement of a Tracking Stock Obligation (as defined in the Inter-Group
Agreement) incurred after the Merger without the approval of Liberty, shall be
for the account of AT&T for purposes of this Agreement. Liberty agrees that,
except as set forth in the preceding sentence, any Tax liability (or any
reduction in a Tax benefit attributable to the Common Stock Group under this
Agreement) incurred as a result of the Tax Law Change (including as a result

9

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of the settlement of a Tracking Stock Obligation existing at the time of the
Merger (or incurred after the Merger with the approval of Liberty) satisfied, as
directed by Liberty) shall be for the account of Liberty for purposes of this
Agreement.

         (ii)  Responsibility for DITS.    (A) Except for the Exhibit D DITS,
any DITS created in any taxable period ending on or prior to the Closing Date,
any DITS created pursuant to the TCI Pre-AT&T Merger Restructuring Plan, and any
DIT created pursuant to the transactions contemplated by the Letter Agreement
(the "Letter Agreement") dated February 11, 1999 among AT&T, TCI and Liberty (a
"Sprint DIT"), in each case, brought into income as the result of any
deconsolidation of the Liberty Group or the liquidation of Encore Media
Group LLC, a Colorado limited liability company, or other entity conducting the
Encore/Starz business shall be for the account of the Liberty Group, and Liberty
shall pay AT&T any Tax (or any reduction in any Tax refund, credit or other
benefit) attributable thereto; (B) any Exhibit D DITS shall be for the account
of the Common Stock Group; and (C) except as otherwise provided in clause (A) or
(B) above, any DIT created in any taxable period ending after the Closing Date
that is brought into income as the result of the deconsolidation of the Liberty
Group shall be the obligation of the Group that includes the Legal Entity that
is the selling member (within the meaning of the Consolidated Return
Regulations), unless otherwise agreed upon by AT&T and Liberty.

        (iii)  No Acceleration of DITS.    Without the prior written consent of
AT&T, unless the Liberty Group agrees to assume the Tax burden thereof, the
Liberty Group shall not take any action (inadvertent or otherwise) that would
cause an acceleration of income arising from any DIT that is disclosed in Part 2
of Section 5.10(b) of the Company Disclosure Statement or from any Exhibit D DIT
or from any Sprint DIT; provided, however, that restoral of income or gain from
a DIT that occurs as a result of depreciation or amortization deductions taken
by the Liberty Group shall not be considered an acceleration of any DIT.

        (iv)  Accounts Under Old TCI Tax Sharing Agreements.    The intercompany
accounts reflecting the obligation of the Liberty Group (approximately
$237 million as of the date of this Agreement) for periods on or prior to the
Closing Date under the 1995 TCI Tax Sharing Agreement (the "Intercompany
Account") shall be paid by Liberty at such time, if any, that the Liberty Group
deconsolidates from the AT&T Affiliated Group for federal income Tax purposes;
provided, however, that (A) the amount of the Intercompany Account shall be
determined pursuant to the provisions of the 1995 TCI Tax Sharing Agreement and
without regard to clause 3(d)(v) below; (B) the Legal Entities listed on
Exhibit A shall be treated as Liberty Group members for all relevant periods for
purposes of calculating the Intercompany Account and (C) the amount of the
Intercompany Account shall be reduced by an amount equal to the product of
20 percent and the amount of any income or gain arising from the exercise, and
the sale of assets pursuant thereto, of the option that was granted pursuant to
the Option Agreement, dated June 24, 1997, among RET Corporation, Southern
Satellite Systems, Inc., et. al., to purchase certain assets of Southern
Satellite Systems, Inc., LMC Satcom, Inc., and Royal Communications, Inc.. All
"Benefit Tracking Accounts" and "AMT/Regular Tax Adjustments" under the 1997 TCI
Tax Sharing Agreement shall be eliminated as of the Closing Date without any
obligation or payment with respect thereto and no rights or obligations shall
subsequently arise with respect thereto;

         (v)  Pre-Closing Losses; Pre-Closing Alternative Minimum Tax.    For
taxable periods ending on or prior to the Closing Date: (A) net operating loss
carryovers, current losses and other Tax attributes available to the TCI
Affiliated Group may be used by any member of the TCI Affiliated Group without
compensation to the Group generating such attributes, (B) if the TCI Affiliated
Group has only actual alternative minimum Tax liability in a Taxing
jurisdiction, Liberty

10

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shall pay AT&T for any alternative minimum Tax losses with respect to such
jurisdiction generated by the Legal Entities in the TCI Affiliated Group that
are not in the Liberty Group that reduce such liability with respect to such
jurisdiction, and AT&T shall pay Liberty for any alternative minimum Tax losses
generated by the Liberty Group that reduce such liability with respect to such
jurisdiction, and (C) if the TCI Affiliated Group has only actual alternative
minimum Tax liability in a Taxing jurisdiction, except as provided in clause (B)
above, Liberty shall not be required to pay its share;

        (vi)  TCI Affiliated Group Non-NOL Carryover.    For taxable periods
beginning after the Closing Date, any TCI Affiliated Group Non-NOL Carryover
shall be treated as a Tax Item of the Common Stock Group;

       (vii)  The Unused TCI Affiliated Group NOL.    The Unused TCI Affiliated
Group NOL shall be available to offset any payment obligation incurred by the
Liberty Group pursuant to Section 3(a)(i) hereof at the applicable federal
income tax rate for the taxable period with respect to which such payment
obligation of the Liberty Group is incurred (without regard to whether the AT&T
Affiliated Group is subject to separate return limitation year, Section 382 or
other restrictions, in each case, arising by reason of the Merger, on the
utilization of the Unused TCI Affiliated Group NOL in a taxable period, or
portion thereof, beginning after the Closing Date); provided, however, that to
the extent that the Unused TCI Affiliated Group NOL is a TCI SRLY NOL or a
Liberty SRLY NOL it shall only be utilized as set forth in this paragraph below.
In the case of any portion of the Unused TCI Affiliated Group NOL arising in a
member of the Liberty Group which is subject to separate return limitation year,
Section 382 or other restrictions arising prior to the Merger Date (a "Liberty
SRLY NOL"), such Liberty SRLY NOL shall be available to reduce the Liberty
Group's payment obligation only to the extent such Liberty SRLY NOL is actually
utilized by the AT&T Affiliated Group. In the case of any portion of the Unused
TCI Affiliated Group NOL arising in a member of the TCI Group which is subject
to separate return limitation year, Section 382 or other restrictions arising
prior to the Merger Date (a "TCI SRLY NOL"), such TCI SRLY NOL shall be
available to reduce the Liberty Group's payment obligation only when an amount
of the TCI Affiliated Group NOL in excess of the sum of the Liberty SRLY NOL and
the TCI SRLY NOL has previously offset such payment obligation and then only as,
when and to the extent that the AT&T Affiliated Group has actually utilized such
TCI SRLY NOL or can be Reasonably Expected to so utilize such TCI SRLY NOL. For
these purposes, the AT&T Affiliated Group shall be "Reasonably Expected" to
utilize a TCI SRLY NOL if and to the extent, through use of its reasonable best
efforts, such NOL could have been utilized. Such reasonable best efforts shall
not require the aggregate cost or expense to AT&T (including AT&T's share of the
costs and expenses of the Arbiter) in excess of 12.5 million dollars, it being
agreed and understood that AT&T will continue to use its reasonable best efforts
at the Liberty Group's reasonable request and at the Liberty Group's expense to
utilize such NOL. Within six weeks of the date hereof the parties shall
designate a mutually acceptable neutral arbiter (the "Arbiter") to resolve any
disputes with respect to the calculation of the Reasonably Expected utilization
of such TCI SRLY NOL and also with respect to when or whether AT&T has incurred
aggregate cost or expense in excess of 12.5 million dollars. The costs and
expenses of the Arbiter shall be shared equally between AT&T and Liberty;

      (viii)  Payment for NOL.    Upon any deconsolidation of Liberty from the
AT&T Affiliated Group for federal income Tax purposes, AT&T shall pay Liberty an
amount equal to the product of (A) the Unused TCI Affiliated Group NOL (reduced
by any Liberty SRLY NOL not utilized by the AT&T Affiliated Group and, without
duplication, any portion of the Unused TCI Affiliated Group NOL that will become
a Tax Item of Liberty or its Affiliates under the law upon such deconsolidation)
that has been, or is reasonably expected to be (or, in the case of the TCI SRLY
NOL, that has been or is Reasonably Expected to be), utilized by the AT&T
Affiliated Group for

11

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federal income tax purposes and (B) 35 percent. AT&T agrees to provide written
notice to Liberty of the amount that will be paid pursuant to this
Section 3(d)(viii) thirty days prior to the anticipated deconsolidation date of
the Liberty Group. If any amount of the Unused TCI Affiliated Group NOL as of
the date of deconsolidation is actually utilized by the AT&T Affiliated Group
after the deconsolidation date of the Liberty Group, and Liberty has not been
paid for such Unused TCI Affiliated Group NOL pursuant to this Section (such
amount shall be referred to as the "Unpaid NOL"), AT&T shall pay Liberty, within
5 business days after the Tax Return utilizing the Unpaid NOL has been filed, an
amount equal to the product of (C) the Unpaid NOL that has been utilized and
(D) 35 percent. If any TCI Affiliated Group NOL for which Liberty has been paid
pursuant to this Section 3(d)(viii) expires unutilized (whether by reason of any
separate return limitation year or Section 382 restriction or otherwise),
Liberty shall repay AT&T the amount of the payment in respect of such expired
TCI Affiliated Group NOL, plus interest at 6.5 percent, compounded annually,
from the date of deconsolidation. AT&T (subject, in the case of the TCI SRLY
NOL, to the provisions of clause (vii) above) and TCI each agree to use
reasonable efforts to have the TCI Affiliated Group NOL utilized by the AT&T
Affiliated Group;

        (ix)  Post-Closing Compensation Deductions.    Each Group shall be
entitled to the deductions arising after the Closing Date from the exercise by,
or settlement of, any stock options or other equity-linked incentives, including
stock appreciation rights, "phantom" stock rights and similar equity-linked
instruments (A) by any person who is an officer, employee or consultant of such
Group at the time of such exercise or settlement and (B) by any person who is no
longer an officer, employee or consultant of either Group at the time of such
exercise or settlement but who was an officer, employee or consultant of such
Group on the date of such person's last employment by either Group, in each
case, regardless of whether the stock underlying the option or equity-linked
incentive tracks the Common Stock Group or the Liberty Group. Each Group shall
be entitled to the deductions arising after the Closing Date from the payment of
other compensation to the extent that such Group bears the cost of such
compensation; and

         (x)  Warrants.    The parties agree that Liberty's basis in the
Warrants equals $8.25 per Warrant, which is the fair market value of the
Warrants as agreed by AT&T and Liberty and the purchase price paid for the
Warrants by Liberty in a closing transaction, and that they shall take no action
inconsistent with such basis (including in connection with filing Tax Returns),
unless required pursuant to a Final Determination.

        4.    Subsidiary Payments.    Each of the Subsidiaries of the Liberty
Group agrees to pay to Liberty or at Liberty's discretion, to AT&T its share of
each of the payments for which Liberty is responsible hereunder no later than
one business day prior to the date upon which the relevant payment by Liberty is
required to be made hereunder.

        5.    Adjustments.    

        (a)   In the event of any Redetermination of any Joint Return for any
taxable period, the amounts required to be paid pursuant to Section 3 shall be
recomputed for such taxable period to take into account such Redetermination,
and payments pursuant to Section 3 hereof shall be appropriately adjusted.
Liberty shall pay AT&T or AT&T shall pay Liberty an amount equal to the
difference between the payment or payments previously made between the parties
in respect of such redetermined Tax Return and the amount that would have been
paid pursuant to this Agreement in respect of such redetermined Tax Return if
such redetermined Tax Return had been filed on the basis of the Redetermination,
plus interest at the statutory rate and applicable penalties.

12

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        (b)   In the event of any Redetermination that reduces the amount of the
TCI Affiliated Group NOL, Liberty shall pay AT&T the sum of (A) the amount by
which Liberty's tax sharing obligations were reduced in reliance on the Phantom
NOL pursuant to Section 3(d)(vii), (B) the amount that AT&T paid Liberty
pursuant to Section 3(d)(viii) hereof in reliance on the Phantom NOL and (C)
interest at the statutory rate from the date or dates of such reductions in tax
sharing obligations and payments by AT&T and applicable penalties, and AT&T
shall have no obligation to pay Liberty the amount of any benefit to AT&T
arising as a result of any Redetermination that reduces the amount of the TCI
Affiliated Group NOL. In the event of any Redetermination that reduces the
amount of any Tax Item of the Liberty Group that is a loss, deduction or credit
that was carried back or carried forward and for which Liberty received a
payment hereunder from AT&T (or Liberty's payments hereunder to AT&T were
reduced), Liberty shall pay AT&T the amount of such payment hereunder from
AT&T(or reduction in a payment hereunder by Liberty) plus interest at the
statutory rate and applicable penalties and AT&T shall have no obligation to pay
Liberty the amount of any benefit to AT&T arising as a result of such
Redetermination.

        (c)   Any regular consolidated federal income Tax liability of the TCI
Affiliated Group arising from any Redeterminations of Tax Items of the TCI
Affiliated Group for one or more taxable periods ending on or before the Closing
Date shall be borne by the Common Stock Group and the Liberty Group,
respectively, in proportion to the amount that the sum of all Redeterminations
of Tax Items attributable to the Tax Items of the TCI Group or the Tax Items of
the Liberty Group, respectively, for all such periods bears to the sum of all
Redeterminations of Tax Items attributable to the TCI Affiliated Group for all
such periods.

        (d)   Any alternative minimum consolidated federal tax liability of the
TCI Affiliated Group arising from any Redetermination of Tax Items of the TCI
Affiliated Group for one or more taxable periods ending on or before the Closing
Date shall be borne by the Common Stock Group to the extent that AT&T reasonably
expects to utilize the credit arising from payment of such liability and any
such remaining alternative minimum consolidated federal tax liability shall be
borne by the Group generating such alternative minimum tax liability; provided,
however, that (A) in the event that AT&T utilizes any credit arising from the
alternative minimum tax liability that would otherwise be borne by Liberty, AT&T
shall repay Liberty the amount paid by Liberty to AT&T in respect of such
alternative minimum tax liability and (B) in the event that AT&T reasonably
expects to utilize a credit but is not able to utilize such credit, whether by
reason of expiration, Redetermination or otherwise, Liberty shall pay AT&T the
amount that Liberty would have paid AT&T had AT&T not reasonably expected to
utilize such credit.

        (e)   Notwithstanding any other provision of this Agreement, in the
event of a Final Determination with respect to the Warrants that results in an
increase in basis to Liberty over $8.25 per Warrant (or other property received
in exchange for such Warrant) or over the sum of $8.25 plus the exercise price
in the stock underlying each Warrant (or other property received in exchange for
such stock) ("Excess Basis"), Liberty shall pay to AT&T the amount of any Tax
benefit received by Liberty resulting from such basis increase; provided,
however, that (I) in the event of a deconsolidation of the Liberty Group after
such Final Determination, Liberty shall pay AT&T on the date of deconsolidation
an amount equal to the product of (A) 35 percent and (B) the amount of any
Excess Basis for which AT&T has not previously been paid and (II) in the event
of such a Final Determination after a deconsolidation of the Liberty Group,
Liberty shall pay AT&T within seven days after the date of such Final
Determination an amount equal to the product of 35 percent and the Excess Basis,
plus interest at 6.5 percent, compounded annually, from the date of
deconsolidation.

        (f)    Any payment by Liberty or AT&T required by any Redetermination
shall be paid within seven days after the date of a Final Determination with
respect to such Redetermination.

        6.    Separate Returns.    Any Separate Return that includes only a
member or members of the Liberty Group and any Taxes with respect to such
Separate Return shall be the responsibility of the Liberty

13

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Group provided that the Liberty Group timely files such Separate Returns and
pays the Taxes due with respect thereto. In the event that the Liberty Group
does not so file such a Separate Return or does not pay the Taxes due with
respect thereto, Liberty shall indemnify AT&T with respect to such Separate
Return as provided in Section 8 and, notwithstanding any other provision hereof,
AT&T shall be entitled to file such Separate Return in any manner it chooses so
long as it files such Separate Return in good faith.

        7.    Interest on Unpaid Amounts.    In the event that any party fails
to pay any amount owed pursuant to this Agreement on the date when due, interest
shall accrue on any unpaid amount at the Designated Rate from the due date until
such amounts are fully paid.

        8.    Indemnification.    

        (a)   From and after the Closing Date, each Legal Entity that is a
member of the Liberty Group shall indemnify and hold harmless each Legal Entity
that is a member of the Common Stock Group and their respective directors,
officers, employees, affiliates, agents, successors and assigns (the "Common
Stock Indemnitees") from and against (i) any Taxes which such member of the
Liberty Group is required to pay to a Governmental Authority (without any right
of reimbursement from AT&T) or in respect of which Liberty is required to make a
payment hereunder to AT&T and (ii) any Losses incurred by any Common Stock
Indemnitee by reason of a breach by any member of the Liberty Group of its
obligations or covenants hereunder.

        (b)   From and after the Closing Date, each Legal Entity that is a
member of the Common Stock Group shall indemnify and hold harmless each Legal
Entity that is a member of the Liberty Group and their respective directors,
officers, employees, affiliates, agents, successors and assigns (the "Liberty
Indemnitees") from and against (i) any Taxes which such member of the Common
Stock Group is required to pay to a Governmental Authority (without any right of
reimbursement from Liberty) or in respect of which AT&T is required to make a
payment hereunder to Liberty and (ii) any Losses incurred by any Liberty
Indemnitee by reason of a breach by any member of the Common Stock Group of its
obligations or covenants hereunder.

        9.    Liberty Contests and Filing of Returns.    

        (a)   Tax Returns of the TCI Affiliated Group for taxable periods ending
on or prior to the Closing Date shall be prepared by the TCI Affiliated Group
and approved (which approval shall not be unreasonably withheld) by Liberty, and
shall be forwarded to AT&T for its review and approval (which approval shall not
be unreasonably withheld) prior to filing. Such Tax Returns shall be prepared on
a basis consistent with prior periods except insofar as changes in law require a
change in reporting.

        (b)   From and after the Closing Date, Liberty shall have the right to
control in all respects all Tax Proceedings with respect to any member of the
TCI Affiliated Group with respect to any Pre-Closing Taxable Period; provided,
however, that (i) AT&T shall be entitled to participate in any such Tax
Proceeding at its expense, (ii) Liberty shall keep AT&T updated and informed and
shall consult with AT&T with respect to any contested Tax Item, (iii) Liberty
shall act in good faith with a view to the merits in connection with the Tax
Proceeding and (iv) any proposed settlement shall require the consent of AT&T,
which consent shall not be unreasonably withheld.

        (c)   With respect to any Joint Return for any taxable year ending after
the Closing Date, Liberty shall provide a Tax package for the Liberty Group,
prepared at Liberty's sole cost and expense, to AT&T relating to the Liberty
Group's activities no later than the date (provided that Liberty is given
reasonable notice of such date) required by AT&T of its Significant
Subsidiaries. Such packages shall (A) be prepared by

14

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a nationally recognized accounting firm (the "Package Preparer") mutually
reasonably satisfactory to AT&T and Liberty, (B) take no position with a
likelihood of success under the law that is less than 331/3 percent and include
an opinion of the Package Preparer to such effect and (C) include a list
prepared by the Package Preparer of all positions taken that are not more likely
than not to succeed under the law and an analysis of the issues raised by each
such position. The Joint Return of the AT&T Affiliated Group (including its
consolidated federal income Tax Return) shall be prepared on the basis of the
applicable Tax package prepared in accordance with this Section 9(c); provided,
however, that in the case of any position taken in any such Tax package
(a "Package Position") with which AT&T disagrees, (I) a neutral mutually
reasonably satisfactory nationally recognized law firm shall opine as to whether
the Package Position has a likelihood of success under the law that is less than
331/3 percent and (II) the AT&T Affiliated Group shall take the Package Position
for such period in the applicable Joint Return if such law firm opines that such
likelihood is at least 331/3 percent and shall otherwise take any position that
AT&T deems reasonable in lieu of the Package Position; provided further,
however, that AT&T shall have sole discretion to make all decisions with respect
to any election, accounting method or other position that, if applicable, would
be required to apply to any member of the Common Stock Group (and in the case of
any election that would not, if made, apply to any member of the Common Stock
Group, AT&T shall make such election if requested in Liberty's Tax package and
AT&T shall not make such election if not requested in Liberty's Tax package).
All costs, fees and expenses incurred with respect to the procedures described
in part I of this Section 9(c) shall be borne 75 percent by Liberty and
25 percent by AT&T.

        (d)   With respect to taxable years ending after the Closing Date, AT&T
shall have the right to control in all respects (including settlement) all Tax
Proceedings with respect to any member of the Liberty Group; provided, however,
that (A) Liberty (and any other member of the Liberty Group to the extent such
member's Tax Items are Contested Liberty Group Items in the Tax Proceeding)
shall be entitled to participate in any such Tax Proceeding at their expense,
insofar as the Tax liabilities of the Liberty Group are concerned, (B) AT&T
shall keep Liberty updated and informed, and shall consult with Liberty, with
respect to any Tax Item of the Liberty Group that is a subject of such Tax
Proceeding (a "Contested Liberty Group Item"), (C) AT&T shall act in good faith
with a view to the merits in connection with the Tax Proceeding and (D) without
limiting in any respect AT&T's right to settle any such Tax Proceeding in its
absolute discretion, in the event that Liberty objects to a settlement of a
Contested Liberty Group Item that it has identified in a written notice to AT&T
prior to settlement as an item to be subject to this clause (D), (x) a neutral
nationally recognized accountant (the "Settlement Advisor") that is mutually
reasonably satisfactory to the parties shall determine the extent, if any, to
which the amount for which the Contested Liberty Group Item was settled exceeds
the amount at which the Contested Liberty Group Item could reasonably have been
expected to be settled (the "Tentative Settlement Overpayment"), (y) the
Settlement Advisor shall reasonably reduce the Tentative Settlement Overpayment
to take account of the settlement of any Contested Liberty Group Items (and the
resolution of any items of the Liberty Group for the period settled that were
not the subject of the Tax Proceeding but were specifically identified in a
written notice to Liberty from AT&T and discussed with Liberty prior to
settlement) at an amount lower than the amount at which such items could
reasonably have been expected to be settled (the Tentative Overpayment after
such reduction, if any, the "Settlement Overpayment") and (z) AT&T shall pay
Liberty as a Tax sharing payment the excess of the aggregate Settlement
Overpayments for a taxable jurisdiction for a taxable year over the lesser of
(I) 25 percent of the amount at which the Contested Liberty Group Items could
reasonably have been expected to be settled, as determined by the Settlement
Advisor, and (II) $10 million in the case of consolidated federal income Taxes
($2 million in the case of all other Taxes). To the extent that any payment by
AT&T pursuant to clause (z) above arises from an adjustment of a Timing Item
(such payment, an "Advance"), amounts that would otherwise be payable by AT&T to
Liberty with respect to the year that the Corresponding Item is realized shall
be reduced (or amounts that would otherwise have been receivable by AT&T from
Liberty shall be increased) by the amount of the Advance. Liberty shall pay AT&T
the amount of any Advance that has not previously been so applied to reduce (or
increase) payments at such time, if any, that the Liberty Group (or the member
of the Liberty Group to which the Advance relates)

15

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deconsolidates from the AT&T Affiliated Group. All costs, fees and expenses of
the Settlement Advisor and the procedures described in Section 9(d)(D)(x) and
(y) shall be borne 50 percent by Liberty and 50 percent by AT&T.

        10.    Appointment of AT&T as Agent.    Liberty and each of the
Subsidiaries in the Liberty Group hereby appoint AT&T as their agent for the
purpose of filing consolidated federal income Tax Returns that are Joint Returns
and for making any election (described in Section 9(c) of this Agreement) or
application or taking any action in connection with any such Tax Return on
behalf of Liberty and each such Subsidiary in the Liberty Group included in such
return consistent with the terms of this Agreement. Liberty and each of the
Subsidiaries in the Liberty Group hereby appoint AT&T as their agent for the
purpose of filing any other Joint Returns, and for making any election
(described in 9(c) of this Agreement) or application or taking any action in
connection with any such Joint Return on behalf of Liberty and each Subsidiary
in the Liberty Group consistent with the terms of this Agreement. Liberty and
each of the Subsidiaries in the Liberty Group hereby consent to the filing of
such consolidated federal income Tax Returns and combined, consolidated or
unitary state, local or foreign Tax Returns, and to the making of such elections
and applications. Liberty agrees that Liberty and each of the Subsidiaries in
the Liberty Group will be included, to the extent permitted by applicable law,
in the filing of consolidated federal income Tax Returns on behalf of the AT&T
Affiliated Group for each taxable period ending after the Closing Date and will
be included in any other Joint Return required or permitted by applicable law,
which Joint Return AT&T elects or is required to file or cause to be filed.

        11.    Cooperation.    

        (a)   The parties shall cooperate with one another in all matters
relating to Taxes. The Liberty Group shall each provide AT&T with such
cooperation and information as is necessary in order to enable AT&T to satisfy
its tax, accounting and other legitimate requirements. Such cooperation and
information by the members of the Liberty Group shall include making their
respective knowledgeable employees available during normal business hours,
providing the information required by reasonable AT&T Tax and accounting
questionnaires (at the times and in the format required by AT&T of its
Significant Subsidiaries), maintaining such books and records and providing such
information as may be necessary or useful in the filing of Joint Returns and
Separate Returns, and executing any documents and taking any actions which AT&T
may reasonably request in connection therewith. AT&T shall provide Liberty, upon
request, with copies of any Joint Returns filed by AT&T that include any member
of the Liberty Group, promptly after such Joint Returns are filed and with
copies of schedules and workpapers used to prepare such Joint Returns and to
determine payments pursuant to this Agreement.

        (b)   AT&T, Liberty and the Covered Entities shall consult with and
cooperate with one another with respect to any restructuring (including, without
limitation, any incorporation, sale, transfer or exchange of assets and any
liquidation, sale, transfer or reorganization of any entity (such a
restructuring, a "Post-Closing Transaction")) of the assets or entities that
were part of the transactions described in the TCI Pre-AT&T Merger Restructuring
Plan or paragraph 1 of the Letter Agreement to the extent that such
restructuring would reasonably be expected to adversely affect the Tax treatment
of any of the steps listed in the TCI Pre-AT&T Merger Restructuring Plan or
paragraph 1 of the Letter Agreement materially. If the Liberty Group has not
given its approval to a Post-Closing Transaction effected by any member of the
Common Stock Group, which approval shall not be unreasonably withheld (provided
that reasonableness shall be based on risk, not dollars), and such Post-Closing
Transaction affects the Tax treatment of any step in the TCI Pre-Merger
Restructuring Plan or paragraph 1 of the Letter Agreement creating either a Tax
liability or a DIT or a reduction in any Tax benefit that would otherwise be for
Liberty's account under this Agreement, then (A) AT&T shall indemnify Liberty
for (i) the amount of any reduction of the TCI Affiliated Group NOL that would
not have arisen but for such Post-Closing Transaction, (ii) any Tax created from
any DIT that would not have arisen but for such Post-Closing Transaction, and
(iii) any other Tax liability (or reduction in any Tax benefit) that would

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not have arisen but for such Post-Closing Transaction and (B) AT&T shall be
entitled, notwithstanding any other provision of this Agreement, to control any
Tax Proceeding to the extent it relates to any Tax liability, reduction in Tax
benefit or reduction in the TCI Affiliated Group NOL arising from such
Post-Closing Transaction. If AT&T has not given its approval to a Post-Closing
Transaction effected by any member of the Liberty Group, which approval shall
not be unreasonably withheld (provided that reasonableness shall be based on
risk, not dollars), and such Post-Closing Transaction affects the Tax treatment
of any step in the TCI Pre-Merger Restructuring Plan or paragraph 1 of the
Letter Agreement creating either a Tax liability or a DIT or a reduction in any
Tax benefit that would otherwise be for AT&T's account under this Agreement,
then Liberty shall indemnify AT&T for (i) the amount of any reduction of any TCI
Affiliated Group Non-NOL Carryover that would not have arisen but for such
Post-Closing Transaction, (ii) any Tax created from any DIT that would not have
arisen but for such Post-Closing Transaction, and (iii) any other Tax liability
(or reduction in any Tax benefit) that would not have arisen but for such
Post-Closing Transaction.

        12.    Confidentiality.    Any information obtained by any party under
this Agreement shall be kept confidential, except as may be necessary in
connection with the filing of Tax Returns or claims for refund or in connection
with an audit, dispute, proceeding, suit or action concerning any issues or
matters addressed in this Agreement, or unless a party is compelled to disclose
information by judicial or administrative process or, in the opinion of its
counsel, by other requirements of law. This Section 12 shall not be construed to
prevent the sharing of information by the parties with their respective legal
advisors or accountants, the independent certified public accountants for
purposes of performing the duties specified in Section 14 hereof, with the
Settlement Advisor for purposes of performing the duties specified in
Section 9(d) hereof or with the Arbiter.

        13.    Payment of Tax.    For each taxable period, AT&T shall timely pay
or discharge, or cause to be timely paid or discharged, the consolidated federal
income Tax liability of the AT&T Affiliated Group for such taxable period and
the combined state, local or foreign Tax liability shown on any Joint Return
that AT&T or any other member of the Common Stock Group elects or is required to
file.

        14.    Calculation of Tax Sharing Payments and Resolution of
Disputes.    The independent certified public accountants for AT&T shall review
each calculation of payments pursuant to this Agreement and provide a written
certification to Liberty that such payments have been calculated and determined
in accordance with the terms and provisions of this Agreement. Any dispute
concerning the calculation or basis of determination of any payment provided for
hereunder or the interpretation of any term or provision or any matter not
contemplated by this Agreement that cannot be resolved in good faith by the
parties shall be resolved by an independent certified public accounting firm
that is mutually reasonably satisfactory to AT&T and Liberty in a manner that
best conforms with the intent of the parties in drafting this Agreement, whose
judgment shall be conclusive and binding upon the parties, in the absence of
mathematical error. All costs, fees and expenses of the independent certified
public accounting firms that are attributable to services rendered under this
Section 14 shall be borne half by AT&T and half by Liberty.

        15.    Binding Effect; Successors and Assigns.    This Agreement shall
be binding upon AT&T, Liberty and each Subsidiary that is a signatory hereto and
the Subsidiaries that become parties hereto pursuant to Section 23 hereof. This
Agreement shall inure to the benefit of, and be binding upon, any successors or
assigns of the parties hereto (including, without limitation, any Subsidiary
that becomes a party hereto pursuant to Section 23). AT&T, Liberty and each
other party hereto may assign their right to receive payments under this
Agreement but may not assign or delegate their obligations hereunder; provided,
however, that concurrently with the Liberty Media Corporation Contribution (as
defined in the Contribution Agreement) which will occur as soon as practicable
after the occurrence of a Triggering Event (as defined in the Contribution
Agreement), Liberty Group LLC shall assume all the obligations of Liberty and
each other member of the Liberty Group hereunder (and which obligations
thereafter shall be exercisable against Liberty

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Group LLC, as well as Liberty and each other member of the Liberty Group, for
all purposes of this Agreement), and Liberty shall assign all of the rights of
Liberty under this Agreement to Liberty Group LLC (and which rights thereafter
shall be exercisable by Liberty Group LLC for all purposes of this Agreement, on
behalf of Liberty or otherwise), including, without limitation, Liberty's rights
to tax sharing payments and indemnification from AT&T and Liberty's rights to
file certain Tax Returns, to prepare Tax packages, to control or participate in
Tax Proceedings, to object to settlements by AT&T, to cooperation from AT&T, and
to procedures for the calculation of payments and resolution of disputes.

        16.    Interpretation.    This Agreement is intended to calculate and
allocate certain federal, state, local and foreign Tax liabilities of the
members of the AT&T Affiliated Group, the Common Stock Group, and the Liberty
Group, and any situation or circumstance concerning such calculation and
allocation that is not specifically contemplated hereby or provided for herein
shall be dealt with in a manner consistent with the underlying principles of
calculation and allocation in this Agreement. This Agreement shall not be
interpreted to require any payment by Liberty to AT&T that is duplicative of any
gross proceeds retained by AT&T for taxes pursuant to part (a) of the definition
of "Liberty Media Group Net Proceeds" found in Section 9, Part B, of Article
Third of the AT&T Charter.

        17.    Legal and Accounting Fees.    Unless otherwise specified herein,
any fees or expenses for legal, accounting or other professional services
rendered in connection with the preparation of a Joint Return or the conduct of
any Tax Proceeding shall be allocated between AT&T and Liberty in a manner
resulting in AT&T and Liberty, respectively, bearing a reasonable approximation
of the actual amount of such fees or expenses hereunder reasonably related to,
and for the benefit of, their respective Groups.

        18.    Effect of the Agreement.    This Agreement shall determine the
liability of AT&T, Liberty and the members of their respective Groups to each
other as to the matters provided for herein, whether or not such determination
is effective for purposes of the Code or of state, local or foreign Tax laws, or
for financial reporting purposes or for any other purposes.

        19.    Entire Agreement.    

        (a)   This Agreement embodies the entire understanding among the parties
relating to its subject matter and supersedes and terminates any prior
agreements and understandings among the parties with respect to such subject
matter (including the 1995 TCI Tax Sharing Agreement and the 1997 TCI Tax
Sharing Agreement, each of which shall be of no further force or effect, and
Exhibit C to the Merger Agreement), and no Person shall have any right,
responsibility, obligation or liability thereunder. Any and all prior
correspondence, conversations and memoranda (including the memorandum from AT&T
and Liberty to Wachtell, Lipton, Rosen & Katz and Baker & Botts, L.L.P. dated
March 4, 1999) are merged herein and shall be without effect hereon. No
promises, covenants or representations of any kind, other than those expressly
stated herein, have been made to induce either party to enter into this
Agreement. This Agreement, including this provision against oral modification,
shall not be modified or terminated except by a writing duly signed by each of
the parties hereto, and no waiver of any provisions of this Agreement shall be
effective unless in a writing duly signed by the party sought to be bound.

        (b)   Notwithstanding Section 19(a), the Federal Tax Allocation
Agreement, the State and Local Income Tax Allocation Agreement and the Tax
Sharing Agreement by and among AT&T, Lucent Technologies Inc. and NCR
Corporation dated as of February 1, 1996 shall each remain fully in effect;
provided, however, that no Legal Entity included in the Liberty Group shall be
considered a party to such agreements or subject to such agreements.

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        20.    Code References.    Any references to the Code or Treasury
Regulations shall be deemed to refer to the relevant provisions of any successor
statute or regulation and shall refer to such provisions as in effect from time
to time.

        21.    Notices.    Any payment, notice or communication required or
permitted to be given under this Agreement shall be in writing (including
telecopy communication) and mailed, telecopied or delivered:

If to AT&T or any member of the Common Stock Group:
AT&T Corp. 295 North Maple Avenue Basking Ridge, New Jersey 07920 Attention:  
Vice President—Law     and Corporate Secretary Facsimile:   (908) 221-6618
with a copy to:
Wachtell, Lipton, Rosen & Katz 51 West 52/nd/ Street New York, New York 10019
Attention:   Richard D. Katcher, Esq.     Steven A. Rosenblum, Esq. Facsimile:  
(212) 403-2000
If to Liberty or any member of the Liberty Group:
Liberty Media Corporation 8101 East Prentice Avenue, Suite 500 Englewood,
Colorado 80111 Attention:   Peter Zolintakis Facsimile:   (303) 488-3268
with a copy to:
Baker & Botts, L.L.P. 599 Lexington Avenue New York, New York 10022 Attention:  
Elizabeth M. Markowski, Esq.     Frederick H. McGrath, Esq. Facsimile:  
(212) 705-5125

or to any other address as AT&T or Liberty shall furnish in writing to one
another. All such notices and communications shall be effective when received.

        22.    Counterparts.    This Agreement may be executed in two or more
counterparts, each of which shall be deemed to be an original, but all of which
together shall constitute one and the same instrument.

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        23.    New Members.    Each of the parties to this Agreement recognizes
that from time to time, new Subsidiaries of Liberty may be added to the Liberty
Group. Each of the parties agree that any new Subsidiary that is part of the
Liberty Group shall, without the express written consent of the other parties,
become a party to this Agreement for all purposes of this Agreement with respect
to taxable periods ending after such Subsidiary was added to the Liberty Group.

        24.    Nature of Obligations.    Each of AT&T and Liberty acknowledges
and agrees that its respective obligations under this Agreement shall not be
affected by any impossibility, illegality, impracticability, frustration of
purpose, force majeure, act of government, bankruptcy or insolvency of any party
to this Agreement, failure or refusal of any party to this Agreement to perform
its obligations hereunder, dispute, setoff or counterclaim, change in amount,
composition or terms of the assets, liabilities or equity of AT&T or Liberty or
any other party to this Agreement, or any other defense or right which AT&T or
Liberty has or may have that might have the effect of releasing AT&T or Liberty,
as the case may be, from such obligations.

        25.    Termination.    This Agreement shall terminate at such time as
all obligations and liabilities of the parties hereto have been satisfied. The
obligations and liabilities of the parties arising under this Agreement shall
continue in full force and effect until all such obligations have been met and
such liabilities have been paid in full, whether by expiration of time,
operation of law, or otherwise. The obligations and liabilities of each party
are made for the benefit of, and shall be enforceable by, the other parties and
their successors and permitted assigns.

        26.    Liberty Representation.    Liberty represents that Liberty
currently estimates based upon information as of the date hereof that was
provided by TCI personnel to Liberty and evaluated by Liberty personnel in good
faith, that with respect to 1998, for federal income tax purposes, the TCI Group
will have $165 million of alternative minimum taxable income (which reflects a
$70 million alternative minimum taxable loss of National Digital Television
Center, Inc.) and the Liberty Group will have $205 million of alternative
minimum taxable income. It has been the general experience of Liberty that final
federal income tax numbers may vary from such estimates by a considerable
amount, as much as 100 percent or more, but, apart from such general experience,
Liberty has no reason to believe that the numbers contained in the immediately
preceding sentence are incorrect as of the date hereof.

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        IN WITNESS WHEREOF, each of the parties has caused this Agreement to be
executed by its respective duly authorized officer as of the date first set
forth above.

    AT&T CORP.
 
 
By:
 
/s/ Daniel E. Somers

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    Name:   Daniel E. Somers     Title:   Senior Executive Vice President and
Chief Financial Officer
 
 
LIBERTY MEDIA CORPORATION, for itself and for
each member of the Liberty Group
 
 
By:
 
/s/ Charles Y. Tanabe

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    Name:   Charles Y. Tanabe     Title:   Senior Vice President

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Each of the Covered Entities listed below on this page hereby executes this
Agreement as a member of the Liberty Group to acknowledge that such Person is
bound by this Agreement as a member of the Liberty Group:

    TCI WIRELESS HOLDINGS, INC.
 
 
By:
 
/s/ Charles Y. Tanabe

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    Name:   Charles Y. Tanabe     Title:   Senior Vice President
 
 
TCIP, INC.
 
 
By:
 
/s/ Charles Y. Tanabe

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    Name:   Charles Y. Tanabe     Title:   Senior Vice President
 
 
TCI INTERACTIVE, INC.
 
 
By:
 
/s/ Charles Y. Tanabe

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    Name:   Charles Y. Tanabe     Title:   Senior Vice President
 
 
SILVER SPUR LAND AND CATTLE CO.
 
 
By:
 
/s/ Charles Y. Tanabe

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    Name:   Charles Y. Tanabe     Title:   Senior Vice President

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    TELE-COMMUNICATIONS, INC.
 
 
By:
 
/s/ Stephen M. Brett

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    Name:   Stephen M. Brett     Title:   Executive Vice President
 
 
LIBERTY VENTURES GROUP LLC
 
 
By:
 
/s/ Stephen M. Brett

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    Name:   Stephen M. Brett     Title:   Executive Vice President
 
 
LIBERTY MEDIA GROUP LLC
 
 
By:
 
/s/ Charles Y. Tanabe

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    Name:   Charles Y. Tanabe     Title:   Vice President
 
 
TCI STARZ, INC.
 
 
By:
 
/s/ Stephen M. Brett

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    Name:   Stephen M. Brett     Title:   Vice President
 
 
TCI CT HOLDINGS, INC.
 
 
By:
 
/s/ Stephen M. Brett

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    Name:   Stephen M. Brett     Title:   Vice President

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QuickLinks

EXHIBIT 10.1

TABLE OF CONTENTS
TAX SHARING AGREEMENT