EXHIBIT 4.8



                                 THIRD AMENDMENT
                                 ---------------
                                       OF
                                       --
                          CHICAGO TRIBUNE TAX DEFERRED
                          ----------------------------
                         INVESTMENT PLAN FOR MACHINISTS
                         ------------------------------


                  WHEREAS, effective as of January 1, 1986, and pursuant to an
agreement between Chicago Tribune Company (the "Company") and the International
Association of Machinists, Local 126, the Company established the Chicago
Tribune Tax Deferred Investment Plan for Machinists (the "Plan"); and

                  WHEREAS, the Plan has been amended from time to time and
further amendment of the Plan is now considered desirable;

                  NOW, THEREFORE, by virtue and in exercise of the authority
reserved to the Company by Section 10.1 of the Plan, the Plan be and is hereby
further amended in the following particulars:

                  1.       By deleting the last sentence of Paragraph 1.1(d) of
the Plan, effective January 1, 1997.


                  2.       By substituting the following for Paragraph 1.1(k)
of the Plan, effective as of January 1, 1997:

                  "(k)     Employee:  Any Leased Employee and any individual
                           ---------
                           who is classified by the Employer or a Related
                           Company as its common law employee for purposes of
                           employment taxes and wage withholding for Federal
                           incomes taxes. If an individual is not considered an
                           Employee in accordance with the

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                           preceding phrase for a plan year,  a subsequent
                           determination by the Employer or Related Company,
                           any governmental agency or court that the
                           individual is a common law employee of the Employer
                           or Related Company, even if such determination is
                           applicable to prior years, will not have a
                           retroactive effect for purposes of eligibility to
                           participate in the Plan."


                  3.       By substituting the following for Paragraph 1.1(q)
of the Plan, effective as of January 1, 1997:

                  "(q)     Leased Employee:  Any person who is not otherwise an
                           ----------------
                           Employee and who, pursuant to an agreement between
                           the recipient Employer and any other person (the
                           `leasing organization'), has performed services for
                           the Employer, or for the Employer and related persons
                           (determined in accordance with Section 414(n)(6) of
                           the Internal Revenue Code), under the primary
                           direction or control by the Employer or such related
                           persons, on a substantially full time basis for a
                           period of at least one year; provided, that a person
                           shall not be treated as a Leased Employee for any
                           Plan Year if: (i) during such Plan Year, such person
                           is covered by a money purchase pension plan
                           maintained by the leasing organization which provides
                           for immediate participation, full and immediate
                           vesting, and a nonintegrated employer contribution
                           rate of at least 10 percent of such Employee's
                           compensation (as defined in Section 414(n) of the
                           Internal Revenue Code), and (ii) leased employees
                           (determined without regard to this proviso) do not
                           constitute more than 20 percent of the Employer's
                           nonhighly compensated workforce (as defined in
                           Section 414(n) of the Internal Revenue Code)."

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                  4.       By substituting the following for Paragraph 1.1(x) of
the Plan, effective as of January 1, 1998:

                  "(x)     Total Compensation: The earned income, wages,
                           -------------------
                           salaries, fees for professional services, and other
                           amounts received by a Participant for personal
                           services actually rendered in the course of
                           employment with the Employer or a Related Company,
                           determined in accordance with Section 415(a)(3) of
                           the Internal Revenue Code (including, but not limited
                           to, commissions paid to salesmen, compensation for
                           services based on a percentage of profits,
                           commissions on insurance premiums, tips, and bonuses,
                           any elective deferrals (as defined in
                           Section 402(g)(3) of the Internal Revenue Code) and
                           any amount contributed or deferred by the Employer or
                           Related Companies at the Participant's election which
                           is excludable from income under Section 125 of the
                           Internal Revenue Code); provided that a Participant's
                           Total Compensation taken into account for any Plan
                           Year shall be limited to $160,000 or such greater
                           amount as may be determined by the Commissioner of
                           Internal Revenue for that year under
                           Section 401(a)(17) of the Internal Revenue Code.
                           Notwithstanding the previous sentence, a
                           Participant's Total Compensation shall not include
                           the following:

                           (i)      except as provided above, employer
                                    contributions to a plan of deferred
                                    compensation which are not includible in the
                                    Participant's gross income for the taxable
                                    year in which contributed, employer
                                    contributions to a simplified employee
                                    pension plan to the extent such
                                    contributions are deductible by the
                                    Participant, or any distributions from a
                                    deferred compensation plan;

                           (ii)     amounts realized from the exercise of a
                                    non-qualified stock option or when

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                                    restricted stock or property held by the
                                    Participant becomes freely transferable or
                                    is no longer subject to a substantial risk
                                    of forfeiture;

                           (iii)    amounts realized from the sale, exchange, or
                                    other disposition of stock acquired under a
                                    qualified stock option;

                           (iv)     any other amounts which received special tax
                                    benefits, or contributions made by the
                                    Participant (whether or not pursuant to a
                                    salary reduction agreement) towards the
                                    purchase of an annuity described in
                                    Section 403(b) of the Internal Revenue Code
                                    (whether or not such amounts are actually
                                    excludible from the Participant's gross
                                    income); or

                           (v)      any amounts required to be excluded under
                                    Section 415 of the Internal Revenue Code and
                                    the regulations thereunder."

                  5.       By deleting Paragraphs (aa) and (bb) of Section 1.1
from the Plan, effective April 4, 1999.


                  6.       By adding the following Paragraph 2.2(d) to the Plan,
effective as of December 12, 1994:

                  "(d)     Notwithstanding any provision of the Plan to the
                           contrary, contributions, benefits, and service credit
                           with respect to qualified military service will be
                           provided in accordance with Section 414(u) of the
                           Internal Revenue Code."

                                      -4-

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                  7.       By adding the following at the end of Section 3.1 of
the Plan, effective February 3, 1997:

         "Amounts by which a Participant's Compensation is reduced as a Salary
         Reduction Amount for any calendar month shall be paid to the Trustee as
         soon as practicable thereafter, but no later than the 15th business day
         of the next following month. The Committee shall establish a `Salary
         Reduction Account' on behalf of each participant who elects to have
         Salary Reduction Amounts contributed to the plan on his behalf. Salary
         Reduction Accounts shall be invested as provided in Section 5 of the
         Plan."


                  8.       By substituting the following for Paragraph 3.3(b) of
the Plan, effective as of January 1, 1997:

                  "(b)     For the purposes of this Section 3.3:

                           (i)      the term `Highly Compensated Employee' for
                                    any Plan Year means any Covered Employee
                                    who:

                                    (A)     was a five percent owner of
                                            the Employer or any Related
                                            Company during the current or
                                            immediately preceding Plan
                                            Year; or

                                    (B)     received annual compensation
                                            from the Employer or any
                                            Related Company of more than
                                            $80,000 (or such greater
                                            amount as may be determined by
                                            the Commissioner of Internal
                                            Revenue) during the
                                            immediately preceding year and
                                            was

                                      -5-

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                                            in the top-paid 20% of the
                                            employees for such year.

                           (ii)     the term `Average Deferral Percentage' of a
                                    group of Covered Employees for a Plan Year
                                    means the average of the deferral ratios
                                    (determined separately for each Covered
                                    Employee in such group) of (1) to (2),
                                    where (1) equals the Salary Reduction
                                    Amounts elected by and contributed on behalf
                                    of such Covered Employee for such Plan Year,
                                    and (2) equals the Covered Employee's
                                    Compensation for such Plan Year."


                  9.       By substituting the following for subparagraphs
3.3(c)(i) and (ii) of the Plan, effective January 1, 1997:


                           "(i)     the Average Deferral Percentage of all other
                                    Participants for the prior Plan Year
                                    multiplied by 1.25; or

                           (ii)     the Average Deferral Percentage of all other
                                    Participants for the prior Plan Year
                                    multiplied by 2.0; provided that the Average
                                    Deferral Percentage of the Highly
                                    Compensated Employees for such Plan Year
                                    does not exceed that of all other
                                    Participants for the prior Plan Year by more
                                    than two percentage points."


                  10.      By substituting the following for the second sentence
in the paragraph following Paragraph 3.3(c)(ii) of the Plan, effective as
of January 1, 1997:

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                           "If for a Plan Year the Salary Reduction Amounts made
                           on behalf of Highly Compensated Employees exceed the
                           foregoing limitation, the Committee shall refund the
                           excess Salary Reduction Amounts made on behalf of
                           Highly Compensated Employees in the order of their
                           contribution amounts beginning with the largest
                           amount to the extent necessary to meet the foregoing
                           limitation."


                  11.      By deleting the last sentence of Section 4.6 from the
Plan, effective January 1, 1999.

                  12.      By adding the following at the end of Section 5.2 of
the Plan, effective April 4, 1999:

         "One Investment Fund shall be designated as the `Company Stock Fund,'
         which shall be invested primarily in shares of common stock of Tribune
         Company (`Company Stock')."


                  13.      By substituting the following for Section 6.3 of the
Plan, effective April 4, 1999:

         "6.3     Investment of Allocated Employer Contributions

                  "For purposes of investing Employer contributions in
         Investment Funds pursuant to Section 5.2, Employer contributions shall
         be allocated to accounts as provided in Section 6.4."


                  14.      By substituting the following for Section 6.4 of the
Plan, effective April 4, 1999:

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         "6.4     Adjustment of Participants' Accounts

                  Each Participant's account shall be credited with his share of
         Employer contributions as of the date such contributions are received
         by the Trustee or as soon thereafter as practicable and shall be
         charged with the amount of any distribution or other payment as of the
         date such distribution or payment is made or as soon thereafter as
         practicable. For purposes of allocating Employer contributions to
         accounts, the Employer contribution shall be considered allocated to
         accounts as of the last day of the applicable Plan Year. For purposes
         of investing accounts in Investment Funds pursuant to Section 5.2,
         Employer contributions shall be allocated to accounts as soon as
         practicable after they are received by the trustee in accordance with
         rules established by the Committee. Each account shall be adjusted to
         reflect earnings, losses, appreciation and depreciation of the
         Investment Fund or Funds in which the account is invested, or as
         otherwise determined to reasonably reflect the investment of the
         account. Each account shall be adjusted to reflect changes in the
         Investment Funds in which such account is invested pursuant to
         Participant direction in accordance with Section 5.2. Any credit,
         charge or adjustment made pursuant to this Section shall be made in
         accordance with rules established by the Committee and applied to all
         Participants on a uniform and nondiscriminatory basis."


                  15.      By adding the following at the end of Section 7.3 of
the Plan, effective April 4, 1999:

         "All distributions to a Participant or Beneficiary shall be made in
         cash; provided, that a Participant or Beneficiary may, upon request
         filed with the Committee in such manner and at such time as the
         Committee may determine, elect to receive all of those amounts credited
         to his accounts which are invested in the Company Stock Fund in whole
         shares of Company Stock."


                  16.      By substituting the following for Section 7.4 of the
Plan, effective April 4, 1999:

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         "7.4     Amount Available for Distribution
                  ---------------------------------

                  The amount available for distribution to a Participant or his
         Beneficiary shall be the balance credited to the Participant's accounts
         as of the date the distribution is made, as determined in accordance
         with rules established by the Committee."


                  17.      By substituting the following for Paragraph 7.5(b) of
the Plan, effective as of January 1, 1997:

                  "(b)     Payments to a Participant shall commence no later
                           than the April 1 of the calendar year next following
                           the later of the calendar year in which the
                           participant attains age 70 1/2 or the calendar year
                           in which the participant terminates employment with
                           the Employer and all Related Companies (the `required
                           commencement date'); provided, however, that the
                           required commencement date of a Participant who is a
                           five percent owner (as defined in Section 416 of the
                           Internal Revenue Code) with respect to the Plan Year
                           ending in the calendar year in which he attains age
                           70 1/2 shall be April 1 of the next following
                           calendar year. Notwithstanding any other provision of
                           the Plan to the contrary, all distributions hereunder
                           shall be made in accordance with the minimum
                           distribution requirements contained in Section
                           1.401(a)(9)-1, and the minimum distribution
                           incidental benefit requirements contained in Section
                           1.401(a)(9)-2 of the proposed Treasury Regulations,
                           or in the corresponding Sections of any final
                           Treasury Regulations issued under Section 401(a)(9)
                           of the Internal Revenue Code."


                  18.      By substituting the following for Paragraph 7.8(b) of
the Plan, effective as of January 1, 1999:


                  "(b)     Definition of Eligible Rollover Distribution.  An
                           --------------------------------------------
                           eligible rollover distribution is any distribution of
                           all

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                           or any portion of the balance to the credit of the
                           distributee, except that an eligible rollover
                           distribution does not include: any distribution that
                           is one of a series of substantially equal periodic
                           payments (not less frequently than annually) made for
                           the life (or life expectancy) of the distributee or
                           the joint lives (or joint life expectancies) of the
                           distributee and the distributee's designated
                           beneficiary, or for a specified period of ten years
                           or more; any distribution to the extent such
                           distribution is required under Section 401(a)(9) of
                           the Internal Revenue Code; any distribution that is a
                           hardship distribution (as described in Section
                           401(k)(2)(B)(i)(IV) of the Internal Revenue Code);
                           and that portion of any distribution that is not
                           includible in gross income."


                  19. By substituting "Committee" for "Administrative Committee"
and "Investment Committee" wherever either of the latter two phrases appears in
Sections 8.4 and 8.5 of the Plan and by adding the following at the end of
Sections 8.1 and 8.2 of the Plan, effective as of January 1, 1996:

         "The Administrative Committee and the Investment Committee have been
         combined into one Committee which, as of January 1, 1996, is known as
         the Tribune Company Employee Benefits Committee and is referred to
         herein as the Committee. The Committee has all of the functions,
         duties, right and responsibilities formerly entrusted to the
         Administrative and Investment Committees."


                  20.      By substituting the following for Paragraph 9.1(a)(i)
of the Plan, effective as of January 1, 1995:

                           "(i)     $30,000 (or such greater amount as may be
                                    determined by the Commissioner of Internal
                                    Revenue for

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                                    the calendar year which begins with
                                    or within that Plan Year); or"


                  21.      By adding the following at the end of Paragraph
9.1(c) of the Plan, ffective January 1, 2000:

         "The provisions of this Paragraph 9.1(c) shall not be effective for any
         Plan Year beginning after December 31, 1999."


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