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                               COUNSELLORS AT LAW

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                                                       DRAFT OF AUGUST 17, 2004


                                                       __________, 2004


[Pioneer Fund]
[Safeco Fund]


Ladies and Gentlemen:

      This opinion is being delivered to you in connection with the Agreement
and Plan of Reorganization (the "Agreement") made as of _______, 2004 by and
between [Pioneer Trust], a [Delaware statutory][Massachusetts business] trust,
on behalf of its series, [Pioneer Fund] ("Acquiring Fund") and [Safeco Trust] on
behalf of its series, [Safeco Fund] ("Acquired Fund"). Pursuant to the
Agreement, Acquiring Fund will acquire all of the assets of Acquired Fund in
exchange solely for (i) the assumption by Acquiring Fund of all of the Assumed
Liabilities, as defined in the Agreement (the "Acquired Fund Liabilities"), and
(ii) the issuance of [Investor Class][Class I] shares of beneficial interest of
Acquiring Fund (the "Acquiring Fund Shares") to Acquired Fund, followed by the
distribution by Acquired Fund, in liquidation of Acquired Fund, of the Acquiring
Fund Shares to the shareholders of Acquired Fund and the termination of Acquired
Fund (the foregoing together constituting the "Transaction"). All section
references, unless otherwise indicated, are to the United States Internal
Revenue Code of 1986, as amended (the "Code").

      In rendering this opinion, we have examined and relied upon (i) the
prospectus for Acquiring Fund dated ______; (ii) the statement of additional
information for Acquiring Fund dated ________; (iii) the prospectus for Acquired
Fund dated ___________; (iv) the statement of additional information for
Acquired Fund dated ____________; (v) the Notice of Meeting of Shareholders
Scheduled for __________ and the accompanying proxy statement and prospectus on
Form N-14 (the "Proxy Statement"); (vi) the Agreement; (vii) the tax
representation certificates delivered pursuant to the Agreement and relevant to
this opinion (the "Representation Certificates"); and (viii) such other
documents as we deemed necessary or relevant to our analysis.

      In our examination of documents, we have assumed the authenticity of
original documents, the accuracy of copies, the genuineness of signatures, and
the legal capacity of signatories. We have assumed that all parties to the
Agreement and to any other documents examined by us have acted, and will act, in
accordance with the terms of such Agreement and documents and that the



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[Pioneer Fund]
[Safeco Fund]
________, 2004
Page 2


Transaction will be consummated pursuant to the terms and conditions set forth
in the Agreement without the waiver or modification of any such terms and
conditions. Furthermore, we have assumed that all representations contained in
the Agreement, as well as those representations contained in the Representation
Certificates are, on the date hereof, and will be, at the consummation of the
Transaction, true and complete in all material respects, and that any
representation made in any of the documents referred to herein "to the knowledge
and belief" (or similar qualification) of any person or party is, and at the
consummation of the Transaction will be, correct without such qualification. We
have also assumed that as to all matters for which a person or entity has
represented that such person is not a party to, does not have, or is not aware
of any plan, intention, understanding, or agreement, there is no such plan,
intention, understanding, or agreement. We have not attempted to verify
independently any of the above assumptions or representations.

      The conclusions expressed herein represent our judgment regarding the
proper treatment of the Transaction under the income tax laws of the United
States based upon the Code, case law, Treasury Regulations, and the rulings and
other pronouncements of the Internal Revenue Service (the "Service") in effect
on the date of this opinion. No assurances can be given that such laws will not
be amended or otherwise changed after the consummation of the Transaction or
that such changes will not affect the conclusions expressed herein.
Nevertheless, we undertake no responsibility to advise you of any developments
after the consummation of the Transaction in the application or interpretation
of the income tax laws of the United States.

      Our opinion represents our best judgment regarding how a court would
decide if presented with the issues addressed herein and is not binding upon the
Service or any court. Moreover, our opinion does not provide any assurance that
a position taken in reliance on such opinion will not be challenged by the
Service and does not constitute any representation or warranty that such
position, if so challenged, will not be rejected by a court.

      This opinion addresses only the specific United States federal income tax
consequences of the Transaction set forth below, and does not address any other
federal, state, local, or foreign income, estate, gift, transfer, sales, or
other tax consequences that may result from the Transaction or any other action
(including any action taken in connection with the Transaction).

      On the basis of and subject to the foregoing and in reliance upon the
representations, facts and assumptions described above, we are of the opinion
that the acquisition by Acquiring Fund of the assets of Acquired Fund solely in
exchange for the issuance of Acquiring Fund Shares to Acquired Fund and the
assumption of the Acquired Fund Liabilities by Acquiring Fund, followed by the
distribution by Acquired Fund, in liquidation of Acquired Fund, of Acquiring
Fund Shares to Acquired Fund shareholders in exchange for their Acquired Fund
Shares and the termination of Acquired Fund, will constitute a "reorganization"
within the meaning of Section 368(a) of the Code. No opinion is expressed or
implied regarding the tax consequences of any other aspects of the Transaction
except as expressly set forth above.


[Pioneer Fund]
[Safeco Fund]
________, 2004
Page 3


      This opinion is being delivered to you solely in connection with the
closing condition set forth in Section [8.5] of the Agreement. This opinion is
intended solely for the benefit of you and the shareholders of the Acquired Fund
and it may not be relied upon for any other purpose or by any other person or
entity, and may not be made available to any other person or entity without our
prior written consent.


                                                Very truly yours,

                                                WILMER CUTLER PICKERING
                                                HALE AND DORR LLP


                                                By:  __________________________