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                                                                     EXHIBIT 10a

                            STOCK PURCHASE AGREEMENT

         This Agreement is made as of this 21st day of September, 1998, by and
between the NINA MASON PULLIAM CHARITABLE TRUST, an Indiana trust (the "Trust"),
and CENTRAL NEWSPAPERS, INC., an Indiana corporation (the "Company").

                                    RECITALS

A.       The Trust holds shares of the Class A common stock of the Company (the
         "Shares").

B.       The Company desires to purchase from the Trust and the Trust desires to
         sell to the Company Two Million Five Hundred Thousand (2,500,000) of
         the Shares (the "Redeemed Shares").

                                    AGREEMENT

         NOW, THEREFORE, in consideration of the mutual promises and covenants
contained herein and subject to and upon the terms and conditions hereinafter
set forth, it is hereby agreed as follows:

                                    ARTICLE I
                           PURCHASE OF REDEEMED SHARES

         1.1 On the date agreed upon by the Trust and the Company as the closing
date of this transaction (the "Closing Date"), the Trust will deliver to the
Company, at the Company's offices in Phoenix, Arizona, the certificate or
certificates representing the Redeemed Shares, a stock power duly executed in
blank and such other instruments as the Company shall deem necessary to transfer
ownership of the Redeemed Shares to the Company. The Company will deliver to the
Trust a certified or cashiers check or wire funds transfer in an amount equal to
One Hundred Fifty Million Dollars ($150,000,000) or $60 per Redeemed Share (the
"Purchase Price") plus interest at the rate of five percent (5%) per annum from
September 16, 1998 through the Closing Date, calculated on the basis of a 365
day year.

         1.2 The Company represents and warrants as follows:

                  (a)      This Agreement is the valid and binding obligation of
                           the Company, enforceable in accordance with its
                           terms, and the execution and performance of this
                           Agreement by the Company will not result in any
                           violation of or be in conflict with or constitute a
                           default under any contract, agreement, instrument,
                           judgment, decree or other indenture to which the
                           Company is a party or by which the Company otherwise
                           is bound; and

                  (b)      No person, corporation or other entity has, nor as a
                           result of the transactions contemplated hereby will
                           have, any right, interest, or valid claim against the
                           Trust, the Company or any other person, for any
                           commission, fee or other compensation as a finder or
                           broker or in any similar capacity arising out of any
                           action taken by the Company.

                                   ARTICLE II
                   REPRESENTATIONS AND COVENANTS OF THE TRUST

The Trust hereby represents and warrants as follows:

                  (a)      As of the Closing Date, the Trust will be the sole
                           owner of the Redeemed Shares, and that each of the
                           Redeemed Shares will be free and clear of liens,
                           encumbrances, claims of others and transfer
                           restrictions of any kind with the exception of any
                           restrictive legend placed on the certificate(s);
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                  (b)      The Trust has full power and authority to sell the
                           Redeemed Shares to the Company in accordance with the
                           provision hereof;

                  (c)      This Agreement is the valid and binding obligation of
                           the Trust enforceable in accordance with its terms,
                           and the execution and performance of this Agreement
                           by the Trust will not result in any violation of or
                           be in conflict with or constitute a default under any
                           contract, agreement, instrument, judgment, decree or
                           other indenture to which the Trust is a party or by
                           which the Trust otherwise is bound;

                  (d)      No person, corporation or other entity has, nor as a
                           result of the transactions contemplated hereby will
                           have, any right, interest, or valid claim against the
                           Trust, the Company or any other person, for any
                           commission, fee or other compensation as a finder or
                           broker or in any similar capacity arising out of any
                           action taken by the Trust; and

                  (e)      The Trust has had access to all information it
                           desires concerning the Company and its subsidiaries
                           and operations, and has had the opportunity to ask
                           such questions of officers of the Company as the
                           Trust has deemed necessary or appropriate in order to
                           enable the Trust to determine whether to authorize
                           the sale of the Redeemed Shares on the terms herein
                           specified. The Trust has reviewed all information it
                           deems material to making its decision to sell the
                           Redeemed Shares hereunder.

                                   ARTICLE III
                                  REGISTRATION

         The Company has agreed to register 1,336,850 shares of its Class A
Common Stock in a registered secondary offering pursuant to a prospectus. The
Trust will pay its own legal and accounting fees, fees for the fairness opinion
received by the Trust, the underwriter's discount and all NASD, SEC and Blue Sky
filing fees related to the secondary offering. The Company will pay all other
fees related to the secondary offering. Any over-allotment shares requested by
the underwriter shall be included in the shares registered by the Company.

                                   ARTICLE IV
                              CONDITIONS PRECEDENT

         All obligations of the parties under this Agreement are subject to the
fulfillment or satisfaction, prior to or as of the Closing Date, of each of the
following conditions precedent:

                  (a)      the arrangement of financing for the transaction on
                           terms and conditions acceptable to the Company;

                  (b)      the receipt of probate court approval for the
                           transaction by the Trust; and

                  (c)      the receipt of fairness opinions for the transaction
                           acceptable to each of the Company and the Trust.

                                    ARTICLE V
                                     GENERAL

         5.1 This Agreement constitutes the entire Agreement between the parties
with respect to the subject matter hereof and supersedes and merges all prior
understandings and agreements concerning the subject matter hereof. This
Agreement may only be modified or amended in writing.

         5.2 This Agreement shall be governed and construed in all respects
under the laws of the State of Indiana.
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         5.3 This Agreement may be executed in counterparts, each one of which
shall constitute one and the same Agreement and each one of which shall be
deemed an original.

         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed as of the date first above written.

                                      CENTRAL NEWSPAPERS, INC.

                                      By:_______________________________________
                                      Thomas K. MacGillivray
                                      Vice President and Chief Financial Officer

                                      THE NINA MASON PULLIAM CHARITABLE TRUST

                                      By:_______________________________________
                                      Printed: Frank Russell
                                      Title: Trustee