<PAGE>   1


                                   EXHIBIT 2.6




                          AGREEMENT AND PLAN OF MERGER


This Agreement and Plan of Merger (this "Agreement") is made as of this 17th day
of December, 1999, by and between American Mutual Holding Company, an Iowa
mutual insurance holding company (to be converted to a stock company pursuant to
Chapters 521A and 508B of the Code of Iowa and renamed "AmerUs Group Co.")
("AMHC"), and AmerUs Life Holdings, Inc., an Iowa corporation ("AMH").

                                    RECITALS

WHEREAS, the Board of Directors of AMHC deems it advisable and in the best
interest of AMHC and its members that AMHC convert into a stock company and
merge with AMH with AMHC as the surviving corporation;

WHEREAS, the Board of Directors of AMH deems it advisable and in the best
interest of AMH and its stockholders that AMH merge with and into AMHC;

WHEREAS, the Board of Directors of AMHC has approved and will recommend to its
members the Plan of Conversion dated as of December 17th, 1999 (the "Plan"),
whereby AMHC shall convert to a stock company, change its name to "AmerUs Group
Co." and merge with AMH, and the Board of Directors of AMH has approved and will
recommend to its stockholders the merger of AMH with and into AMHC, both subject
to the terms set forth herein (the "Merger"); and

WHEREAS, for U.S. federal income tax purposes, it is intended that this
Agreement be a "plan of reorganization" within the meaning of Section 368 of the
Internal Revenue Code of 1986, as amended (the "Code").

NOW, THEREFORE, in consideration of the foregoing, the parties hereto agree as
follows:

                                    Article I
                                     Merger

         Section 1.1 The Merger. Upon the terms and subject to the conditions
set forth herein, and in accordance with Section 521A.14(5) and Chapter 508B of
the Code of Iowa and the Iowa Business Corporation Act (the "IBCA"), AMH shall
be merged with and into AMHC at the Effective Time (as defined below). Following
the Merger, the separate corporate existence of AMH shall cease and AMHC shall
continue under the name "AmerUs Group Co." as the surviving corporation (the
"Surviving Corporation") and shall succeed to and assume all rights and
obligations of each of AMHC and AMH in accordance with Section 521A.14(5) and
Chapter 508B of the Code of Iowa and the IBCA.


<PAGE>   2

         Section 1.2 Effective Time of Merger. The Merger shall become effective
(the "Effective Time") at the date and time set forth in properly executed
articles of merger (the "Articles of Merger") which shall be duly filed by AMHC
and AMH with the Secretary of State of the State of Iowa after all the
conditions set forth in Article VI have been satisfied or waived.

                                   Article II
                              Surviving Corporation

         Section 2.1 Articles of Incorporation. The form of Amended and Restated
Articles of Incorporation attached as Exhibit B to the Plan shall be the
articles of incorporation of the Surviving Corporation, until thereafter changed
or amended as provided therein or by applicable law.

         Section 2.2 By-Laws. The form of Amended and Restated By-laws attached
as Exhibit C to the Plan shall be the By-laws of the Surviving Corporation,
until thereafter changed or amended as provided therein or by applicable law.

         Section 2.3 Directors and Officers. The directors and officers of the
Surviving Corporation shall consist of the directors and officers of AMHC and
AMH in office immediately prior to the Effective Time, until the earlier of
their resignation or removal or until their respective successors are duly
elected or appointed and qualified, as the case may be.

                                   Article III
                     Conversion of Shares; Effect of Merger

         Section 3.1 Conversion; Exchange Ratio. At the Effective Time, by
virtue of the Merger and without any action on the part of any holder of capital
stock of AMH or AMHC:

                  (a) Each share of (i) Class A Common Stock, no par value, of
AMH (the "Class A Shares"), and (ii) Class B Common Stock, no par value, of AMH
(the "Class B Shares," and together with the Class A Shares, the "AMH Shares"),
issued and outstanding immediately prior to the Effective Time (other than
shares to be cancelled in accordance with Section 3.1(b)) shall (subject to
Section 3.1(d)) be converted into the right to receive one validly issued, fully
paid and non-assessable share of Common Stock, no par value, of the Surviving
Corporation ("AMHC Shares") (the "Exchange Ratio"). Certificates for AMHC Shares
will be delivered only in the manner provided by Section 3.3.

                  (b) Each AMH Share held in treasury by AMH and each AMH Share
held by AMHC or any direct or indirect subsidiary of AMHC or AMH immediately
prior to the Effective Time shall be cancelled and retired, and shall cease to
exist, and no consideration shall be delivered in exchange therefor.

                  (c) Each share of Common Stock, no par value, of AMHC issued
and outstanding or issuable pursuant to the Plan immediately prior to the
Effective Time shall, by virtue of the Merger, remain outstanding or issuable as
one fully paid and non-assessable share of Common Stock, no par value, of the
Surviving Corporation.


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<PAGE>   3

                  (d) Notwithstanding anything in this Agreement to the
contrary, AMH Shares held by a person (a "Dissenting Stockholder") who complies
with all the provisions of Iowa law concerning the right of holders of AMH
Shares to dissent from the Merger and require appraisal of their AMH Shares
("Dissenting Shares") shall not be converted as described in Section 3.1(a) but
shall become the right only to receive such consideration as may be determined
to be due to such Dissenting Stockholder pursuant to the laws of the State of
Iowa. If, after the Effective Time, such Dissenting Stockholder withdraws his
demand for appraisal or fails to perfect or otherwise loses his right of
appraisal, in any case pursuant to the IBCA, his AMH Shares shall be deemed
converted as of the Effective Time into the right to receive AMHC Shares as
provided in Section 3.1(a).

         Section 3.2 Exchange of Shares. At the Effective Time, the stock
transfer books of AMH shall be closed as to the holders of capital stock of AMH
immediately prior to the Effective Time and no transfer of capital stock of AMH
by any such holder shall thereafter be made or recognized. If, after the
Effective Time, certificates which represented AMH Shares immediately prior to
the Effective Time are properly presented in accordance with Section 3.3 hereof
to the exchange agent, ChaseMellon Shareholder Services, L.L.C. (hereinafter
referred to as the "Exchange Agent"), such certificates shall be cancelled and
exchanged for certificates representing the number of AMHC Shares into which the
AMH Shares represented thereby were converted in the Merger.

         Section 3.3 Exchange Procedure. (a) At or prior to the Effective Time,
AMHC shall deposit, or shall cause to be deposited, with the Exchange Agent, for
the benefit of the holders of certificates formerly representing AMH Shares
("Old Certificates"), for exchange in accordance with this Article III,
certificates representing the AMHC Shares ("New Certificates") to be issued
pursuant to this Article III in exchange for outstanding AMH Shares.

                  (b) As promptly as practicable after the Effective Time, AMHC
shall send or cause to be sent to each holder of record of AMH Shares
immediately prior to the Effective Time whose shares were converted into the
right to receive AMHC Shares pursuant to Section 3.1 transmittal materials for
use in exchanging such stockholder's Old Certificates for the consideration set
forth in this Article III. AMHC shall cause the New Certificates into which such
stockholder's AMH Shares are converted at the Effective Time to be delivered to
such stockholder upon delivery to and receipt by the Exchange Agent of Old
Certificates representing all such stockholder's AMH Shares (or indemnity
reasonably satisfactory to AMHC and the Exchange Agent, if any of such
certificates are lost, stolen or destroyed). No interest will be paid on any
merger consideration.

                  (c) Until surrendered for exchange in accordance with the
provisions of this Section 3.3, each certificate theretofore representing AMH
Shares (other than shares to be cancelled pursuant to Section 3.1(b) hereof and
Dissenting Shares) shall from and after the Effective Time represent for all
purposes only the right to receive AMHC Shares as set forth in this Agreement.
No dividends or other distributions with respect to AMHC Shares with a record
date occurring after the Effective Time shall be paid to the holder of any
unsurrendered Old Certificate representing AMH Shares converted in the Merger
into the right to receive such AMHC Shares until the holder thereof receives New
Certificates in exchange therefor in



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<PAGE>   4


accordance with the procedures set forth in this Section 3.3. After so receiving
New Certificates, the record holder thereof also shall be entitled to receive
any such dividends or other distributions, without any interest thereon, which
theretofore had become payable with respect to AMHC Shares such holder had the
right to receive upon surrender of the Old Certificates.

         Section 3.4 Transfer Taxes. If any certificate for any AMHC Shares is
to be issued in a name other than the name of the registered owner of the AMH
Shares surrendered, it shall be a condition of such exchange that (i) the person
requesting such exchange shall pay to the Exchange Agent any transfer or other
taxes; or (ii) establish to the satisfaction of the Exchange Agent that all
applicable taxes have been paid or that no taxes are due.

         Section 3.5 Closing. The closing of the transaction contemplated by
this Agreement (the "Closing") shall take place on such date and time and at
such place after satisfaction or waiver of the conditions set forth in Article
VI upon which AMH and AMHC mutually agree and which, to the extent required by
law, are approved by the Iowa Commissioner of Insurance (the "Iowa
Commissioner").

         Section 3.6 No Further Ownership Rights in AMH Stock; No Liability. The
consideration provided pursuant to this Article III to persons identified on the
books and records of AMH as the owners of AMH Shares shall be deemed to have
been paid in full satisfaction of all rights pertaining to the AMH Shares
theretofore existing, and there shall be no further registration of transfers on
the stock transfer books of the Surviving Corporation of the AMH Shares which
were outstanding immediately prior to the Effective Time. None of AMH, AMHC, the
Surviving Corporation or the Exchange Agent shall be liable to any person in
respect of any property delivered in good faith to a public official pursuant to
any abandoned property, escheat or other similar law.

         Section 3.7 AMH Common Stock Rights. Each stock option, restricted
stock award, stock warrant, stock appreciation right and similar common stock
equivalents, instruments or units (each, a "Common Stock Right") outstanding at
the Effective Time which may be exercised for issuance of, converted into or
relating to the AMH Shares (or, in the case of stock appreciation rights, which
are based upon the value of AMH Shares) (each, a "Continuing Common Stock
Right") shall be assumed by AMHC and converted into a stock option, restricted
stock award, a stock warrant or similar common stock equivalent, instrument or
unit, respectively, to purchase, convert into or relate to AMHC Shares (or, in
the case of stock appreciation rights, become based upon the value of AMHC
Shares) wherein (i) the right to purchase or convert into AMH Shares pursuant to
the Continuing Common Stock Right shall be converted into the right to purchase
or convert into that same number of AMHC Shares, (ii) the exercise or conversion
price per share of the AMHC Shares shall be the previous exercise or conversion
price per AMH Share, and (iii) in all other material respects the Continuing
Common Stock Right shall be subject to the same terms and conditions as governed
the Common Stock Right on which it was based, including the length of time
within which the Continuing Common Stock Right may be exercised or converted
(which shall not be extended except that the holder of a Continuing Common Stock
Right who continues in the service of AMHC or a subsidiary of AMHC shall not be
deemed to have terminated service for purposes of determining the Continuing
Common Stock Right exercise or conversion period) and for all Continuing Common



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<PAGE>   5

Stock Rights, such adjustments shall be and are intended to be effected in a
manner which is consistent with Section 424(a) of the Code. At the Effective
Time, AMHC shall assume and adopt the AmerUs Life Holdings, Inc. Non-Employee
Director Stock Plan, the AmerUs Life Holdings, Inc. 1999 Non-Employee Stock
Option Plan, the AmerUs Life Holdings, Inc. Stock Incentive Plan and the AmerUs
Group Co. MIP Deferral Plan, as each such plan is maintained and administered by
AMH at the Effective Time.

                                   Article IV
                         Representations and Warranties

         Section 4.1 Representations and Warranties of AMH.  AMH represents and
warrants to AMHC as follows:

         (a) Organization and Authority. AMH and each of its subsidiaries is a
corporation duly organized, validly existing, and in good standing under the
laws of its jurisdiction of organization, and has full corporate power and
authority to conduct its business and own its property as now conducted and
owned, in each case, except to the extent that the lack of such organization,
existence, good standing, power or authority does not have, nor could reasonably
be expected to have, a Material Adverse Effect (as defined in Section 8.5) on
AMH. Each of AMH and its subsidiaries is duly qualified or licensed and in good
standing as a foreign corporation in each jurisdiction in which the nature of
its business or the ownership or leasing of its property makes such
qualification or licensing necessary other than in such jurisdictions where the
failure to be so qualified or licensed (individually or in the aggregate) would
not result in a Material Adverse Effect with respect to AMH. AMH has the
requisite corporate power and authority to enter into this Agreement and,
subject to approval of this Agreement by the requisite vote of holders of each
of the Class A Shares and Class B Shares, voting as separate classes, and
receipt of necessary regulatory approvals, to consummate the transactions
contemplated hereby. The execution and delivery of this Agreement and the
consummation of the transactions contemplated hereby have been duly and validly
authorized by all necessary corporate action of AMH, except for the required
approval of the stockholders of AMH of this Agreement. This Agreement has been
duly and validly executed and delivered by AMH and, assuming the due and valid
authorization, execution and delivery of this Agreement by AMHC, constitutes a
legal, valid and binding obligation of AMH, enforceable against it in accordance
with its terms, except as enforceability may be limited by bankruptcy and other
similar laws and general principles of equity.

                  (b) Capitalization of AMH; Ownership of Subsidiary Stock. The
authorized capital stock of AMH consists of 180,000,000 Class A Shares,
50,000,000 Class B Shares and 20,000,000 shares of preferred stock, no par value
("AMH Preferred Stock"). At the close of business on November 1, 1999, an
aggregate of 30,070,854 Class A Shares and Class B Shares and no shares of AMH
Preferred Stock were issued and outstanding, with 25,070,854 Class A Shares and
5,000,000 Class B Shares issued and outstanding, respectively, which comprise
all the issued and outstanding shares of capital stock of AMH. All such issued
and outstanding shares of capital stock of AMH have been duly authorized,
validly issued and are fully paid and non-assessable. AMH owns all the
outstanding shares of capital stock of each of AmerUs Life


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<PAGE>   6


Insurance Company, Delta Life Corporation, AmVestors Financial Corporation and
American Capital Management Group, Inc.

                  (c) No Violation of Existing Agreements. Except as set forth
on Schedule 4.1(c), the execution and delivery of this Agreement, together with
all documents and instruments contemplated herein, the consummation of the
transactions contemplated hereby and thereby, and the compliance with the terms,
conditions and provisions hereof by AMH do not (i) contravene any provisions of
AMH's articles of incorporation or by-laws; (ii) conflict with or result in a
breach of or constitute a material default (or an event that might, with the
passage of time or the giving of notice or both, constitute a material default)
or give rise to any right to terminate, cancel or accelerate or to any loss of
material benefit under any of the terms, conditions, or provisions of any
material lease, indenture, mortgage, loan, or credit agreement or any other
agreement or instrument to which AMH is a party or by which it or its assets may
be bound or affected; (iii) violate or constitute a breach of any decision,
judgment or order of any court or arbitration board or of any governmental
department, commission, board, agency or instrumentality, domestic or foreign,
by which AMH is bound or to which it is subject; or (iv) violate any applicable
law, rule, or regulation to which AMH or any of its property is bound, in each
case of clauses (i)-(iv) which has or could reasonably be expected to have a
Material Adverse Effect (as defined in Section 8.5) on AMH.

                  (d) No Consents or Approvals of Governmental Authorities.
Except for any required regulatory approvals, including, without limitation,
approval by the Iowa Commissioner, the Commissioner of Insurance of the State of
Kansas (the "Kansas Commissioner") and any required securities or broker-dealer
approvals and acceptance of the Articles of Merger pursuant to the IBCA, no
consent or approval of, or filing and expiration of a waiting period or a period
for disapproval by, any governmental authority is required for AMH to consummate
the transactions contemplated by this Agreement, except for any such approval
which the failure to obtain would have, or could reasonably be expected to have,
a Material Adverse Effect (as defined in Section 8.5) on AMH.

                  (e) Title to Assets. Each of AMH and its subsidiaries has good
and merchantable title to all material properties and assets which are reflected
and identified as owned by such entities in the financial statements of AMH set
forth in its Quarterly Report on Form 10-Q filed with the Securities and
Exchange Commission (the "SEC") for the fiscal quarter ended September 30, 1999
(the "AMH Quarterly Financial Statements"), other than property disposed of in
the ordinary course of business subsequent to the date of such financial
statements, free and clear of any material mortgage, lien, pledge, charge, claim
or encumbrance, or material right, title and interest in others, except (a) as
reflected or specified in AMH's audited financial statements set forth in its
Annual Report on Form 10-K filed with the SEC for its fiscal year ended December
31, 1998, including the notes thereto and the unaudited quarterly financial
statements of AMH filed on Form 10-Q with the SEC for each of the first three
quarters of 1999, including the notes thereto (collectively, the "AMH Financial
Statements"), (b) the lien of taxes not yet due or payable or being contested in
good faith by appropriate proceedings and (c) such imperfections of title and
encumbrances, if any, as do not materially detract from the value or interfere
with the use of the properties subject thereto or affected thereby or could
otherwise be reasonably expected to result in a Material Adverse Effect (as
defined in Section 8.5) on AMH.



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                  (f) Taxes. Each of AMH and its subsidiaries has filed or
caused to be filed in a timely manner (within any applicable extension periods)
all material tax returns required to be filed by the Code or by applicable state
or foreign tax laws; all taxes shown to be due on such tax returns have been or
will be timely paid in full and no material tax liens have been filed, in each
case, except for filings or payments the absence of which, or liens the
existence of which, would not have nor could reasonably be expected to result in
a Material Adverse Effect (as defined in Section 8.5) on AMH. The Federal
consolidated income tax returns in which AMH and/or any of its subsidiaries
joined have been examined by the Internal Revenue Service for taxable years
through the year ended December 31, 1992 and all material deficiencies resulting
from such examinations have been paid; taxable years through the year ended
December 31, 1996, are currently before the IRS Office of Appeals or under
examination.

                  (g) Undisclosed Liabilities. Except as disclosed in the
Schedules to this Agreement, the AMH Financial Statements, or as incurred in the
ordinary course of business since the date of the AMH Financial Statements,
neither AMH nor any of its subsidiaries has to AMH's knowledge any liabilities
(absolute, accrued, contingent, unknown or otherwise) of a nature which, if
known, would be required to be disclosed on a balance sheet or in the related
notes to the consolidated financial statements prepared in accordance with
generally accepted accounting principles ("GAAP") and which would have, or could
be reasonably expected to have, individually or in the aggregate, a Material
Adverse Effect (as defined in Section 8.5) on AMH.

                  (h) Absence of Material Events. Since September 30, 1999,
there has not been: (a) any change in the business, assets or prospects of AMH
or its subsidiaries which has had or could reasonably be expected to result in a
Material Adverse Effect (as defined in Section 8.5) to AMH, nor, to the
knowledge of AMH, are any such changes threatened, anticipated or contemplated,
or (b) any actual or, to the knowledge of AMH, threatened, anticipated or
contemplated, damage, destruction, loss, conversion, termination, cancellation,
default or taking by eminent domain or other action by governmental authority
which has had or could reasonably be expected to have a Material Adverse Effect
on AMH.

                  (i) Financial Statements. The AMH Financial Statements fairly
present in all material respects the consolidated financial position of AMH and
its subsidiaries as at the respective dates thereof and the consolidated results
of AMH operations and cash flows for the respective periods indicated, in each
case in accordance with GAAP consistently applied, except as may be indicated in
the notes thereto, or, in the case of unaudited interim financial statements, as
may be permitted by GAAP, except for normal and recurring year-end adjustments
and the absence of certain notes.

                  (j) Litigation. Except as set forth in Schedule 4.1(j), there
is no action, suit, investigation or proceeding pending against AMH or its
subsidiaries, or, to AMH's knowledge, threatened against or affecting AMH or its
subsidiaries, before any court or arbitrator or any governmental body, agency or
official relating to the transactions contemplated hereby or which, if
determined or resolved adversely to AMH, could reasonably be expected to have,
individually or in the aggregate, a Material Adverse Effect (as defined in
Section 8.5) on AMH.



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                  (k) Employee Benefit Plans. Each employee benefit plan of AMH
or its subsidiaries (and each related trust, insurance contract or fund) to the
knowledge of AMH is being maintained and administered in compliance with its
terms and to the knowledge of AMH, AMH has complied in form and in operation in
all respects with the applicable requirements of all laws, regulations and
rulings, including but not limited to ERISA and the Code, and all amounts due
thereunder have been paid, except, in each case to the extent that any such
non-compliance would not, nor could reasonably be expected to result in a
Material Adverse Effect (as defined in Section 8.5) on AMH.

                  (l) Compliance With Laws. To the knowledge of AMH, neither AMH
nor any of its subsidiaries is in conflict with, or in default or violation of
any law, rule, regulation, order, judgment or decree applicable to AMH or any of
its subsidiaries or by which AMH or any of its subsidiaries or any of their
respective properties is bound or affected, in each case except for such matters
which do not have, nor could reasonably be expected to have, a Material Adverse
Effect (as defined in Section 8.5) on AMH. To the knowledge of AMH, (i) no
investigation or review by any governmental entity is pending or threatened
against AMH or any of its subsidiaries, nor has any governmental entity
indicated an intention to conduct the same and (ii) there is no material
judgment, injunction, order or decree binding upon AMH or any of its
subsidiaries, in each case except for such matters which do not have, nor could
reasonably be expected to have, a Material Adverse Effect (as defined in Section
8.5) on AMH.

                  (m) Environmental Matters. Except as set forth in Schedule
4.1(m), to the knowledge of AMH, each of AMH and its subsidiaries is in material
compliance with all applicable federal, state and local laws and regulations
relating to pollution or protection of human health or the environment
(including, without limitation, ambient air, surface water, ground water, land
surface or subsurface strata), including, without limitation, laws, standards
and regulations relating to emissions, discharges, releases or threatened
releases of chemicals, pollutants, contaminants, wastes, toxic substances
hazardous substances, or conditions, petroleum and petroleum products
("Materials of Environmental Concern"), or otherwise relating to the
manufacture, processing, distribution, use, treatment, storage, disposal,
transport or handling of Materials of Environmental Concern (collectively,
"Environmental Laws"), which compliance includes, but is not limited to, the
possession by AMH or its subsidiaries of all permits and other governmental
authorizations required under applicable Environmental Laws, and compliance with
the terms and conditions thereof, except in each case any such non-compliance
which does not have, nor could reasonably be expected to have, a Material
Adverse Effect (as defined in Section 8.5) on AMH.

                  Section 4.2 Representations and Warranties of AMHC. AMHC
represents and warrants to AMH as follows:

                  (a) Organization and Authority. AMHC is a mutual insurance
holding company duly organized, validly existing, and in good standing under the
laws of the State of Iowa, and has full corporate power and authority to conduct
its business and own its property as now conducted and owned, except to the
extent that the lack of such organization, existence, good standing, power or
authority does not have, nor could reasonably be expected to have, a Material
Adverse Effect on AMHC. Each of AMHC and its subsidiaries is duly qualified or




                                      -8-
<PAGE>   9

licensed and in good standing as a foreign corporation in each jurisdiction in
which the nature of its business or the ownership or leasing of its property
makes such qualification or licensing necessary other than in such jurisdictions
where the failure to be so qualified or licensed (individually or in the
aggregate) would not have a Material Adverse Effect (as defined in Section 8.5)
on AMHC. AMHC has the requisite corporate power and authority to enter into this
Agreement and, subject to approval of this Agreement by the requisite vote of
its members, and receipt of necessary regulatory approvals, to consummate the
transactions contemplated hereby. The execution and delivery of this Agreement
and the consummation of the transactions contemplated hereby have been duly and
validly authorized by all necessary corporate action of AMHC, except for the
required approval of the members of AMHC of this Agreement. This Agreement has
been duly and validly executed and delivered by AMHC and, assuming the due and
valid authorization, execution and delivery of this Agreement by AMH,
constitutes a legal, valid and binding obligation of AMHC, enforceable against
it in accordance with its terms, except as enforceability may be limited by
bankruptcy and other similar laws and general principles of equity.

                  (b) Capitalization of AMHC. As of the date of this Agreement,
AMHC has no capital stock authorized, issued or outstanding. The authorized
capital stock of AMHC after conversion to a stock company shall consist of
230,000,000 shares of Common Stock, no par value, and 20,000,000 shares of
preferred stock, no par value. The AMHC Shares, when issued in accordance with
this Agreement, shall be duly authorized, validly issued and fully paid and
non-assessable.

                  (c) No Violation of Existing Agreements. Except as set forth
on Schedule 4.2(c), the execution and delivery of this Agreement, together with
all documents and instruments contemplated herein, the consummation of the
transactions contemplated hereby and thereby, and the compliance with the terms,
conditions and provisions hereof by AMHC do not (i) contravene any provisions of
AMHC's articles of incorporation or by-laws; (ii) conflict with or result in a
breach of or constitute a material default (or an event that might, with the
passage of time or the giving of notice or both, constitute a material default)
or give rise to any right to terminate, cancel or accelerate or to any loss of
material benefit under any of the terms, conditions, or provisions of any
material lease, indenture, mortgage, loan, or credit agreement or any other
agreement or instrument to which AMHC is a party or by which it or its assets
may be bound or affected; (iii) violate or constitute a breach of any decision,
judgment or order of any court or arbitration board or of any governmental
department, commission, board, agency or instrumentality, domestic or foreign,
by which AMHC is bound or to which it is subject; or (iv) violate any applicable
law, rule, or regulation to which AMHC or any of its property is bound, in each
case of clauses (i)-(iv) which has or could reasonably be expected to have a
Material Adverse Effect (as defined in Section 8.5) on AMHC.

                  (d) No Consents or Approvals of Governmental Authorities.
Except as stated in the Plan, and except for any required approval by regulatory
authorities, including, without limitation, securities or broker-dealer
approvals, no consent or approval of, or filing and expiration of a waiting
period or a period for disapproval by, any governmental authority is required
for AMHC to consummate the transactions contemplated by this Agreement, except
for filing and acceptance of the Articles of Merger pursuant to the IBCA, which
the failure to obtain



                                      -9-
<PAGE>   10

would have, or could reasonably be expected to have, a Material Adverse Effect
(as defined in Section 8.5) on AMHC.

                  (e) Title to Assets. Each of AMHC and its subsidiaries has
good and merchantable title to all material properties and assets reflected and
identified as owned by such entities in its financial statements dated as of
September 30, 1999 (the "Quarterly AMHC Financial Statements"), other than
property disposed of in the ordinary course of business subsequent to the date
of such financial statements, free and clear of any material mortgage, lien,
pledge, charge, claim or encumbrance, or material right, title and interest in
others, except (a) as reflected in AMHC's audited financial statements for its
fiscal year ended December 31, 1998, including the notes thereto and the
unaudited quarterly financial statements of AMHC for each of the first three
quarters of 1999 (collectively, the "AMHC Financial Statements"), (b) the lien
of taxes not yet due or payable or being contested in good faith by appropriate
proceedings and (c) such imperfections of title and encumbrances, if any, as do
not materially detract from the value or interfere with the use of the
properties subject thereto or affected thereby or could otherwise be reasonably
expected to result in a Material Adverse Effect (as defined in Section 8.5) on
AMHC.

                  (f) Taxes. Each of AMHC and its subsidiaries has filed or
caused to be filed in a timely manner (within any applicable extension periods)
all material tax returns required to be filed by the Code or by applicable state
or foreign tax laws; all taxes shown to be due on such tax returns have been or
will be timely paid in full and no material tax liens have been filed in each
case, except for filings or payments the absence of which, or liens the
existence of which, would have or could be reasonably expected to have a
Material Adverse Effect (as defined in Section 8.5) on AMHC. The Federal
consolidated income tax returns in which AMHC and/or any of its subsidiaries
joined have been examined by the Internal Revenue Service for all taxable years
through the year ended December 31, 1992 and all material deficiencies resulting
from such examinations have been paid; taxable years through the year ended
December 31, 1996, are currently before the IRS Office of Appeals or under
examination.

                  (g) Undisclosed Liabilities. Except as disclosed in the
Schedules to this Agreement, the AMHC Financial Statements or as incurred in the
ordinary course of business since the date of the AMHC Financial Statements,
neither AMHC nor any of its subsidiaries has to AMHC's knowledge any liabilities
(absolute, accrued, contingent, unknown or otherwise) of a nature which, if
known, would be required to be disclosed on a balance sheet or in the related
notes to the consolidated financial statements prepared in accordance with GAAP
and which have, or could be reasonably expected to have, individually or in the
aggregate, a Material Adverse Effect (as defined in Section 8.5) on AMHC.

                  (h) Absence of Material Events. Since December 31, 1998, there
has not been: (a) any change in the business, assets or prospects of AMHC and
its subsidiaries which has had or could be reasonably expected to result in
Material Adverse Effect (as defined in Section 8.5) to AMHC, nor, to the
knowledge of AMHC, are any such changes threatened, anticipated or contemplated
or (b) any actual or, to the knowledge of AMHC, threatened, anticipated or
contemplated, damage, destruction, loss, conversion, termination, cancellation,
default or taking by eminent domain or other action by governmental authority
which has had or could be reasonably expected to have a Material Adverse Effect
on AMHC.




                                      -10-
<PAGE>   11


                  (i) Financial Statements. The AMHC Financial Statements fairly
present in all material respects the consolidated financial position of AMHC and
its subsidiaries as at the respective dates thereof and the consolidated results
of AMHC operations and cash flows for the respective periods indicated, in each
case in accordance with GAAP consistently applied, except as may be indicated in
the notes thereto, or, in the case of unaudited interim financial statements, as
may be permitted by GAAP, except for normal and recurring year-end adjustments
and the absence of notes.

                  (j) Litigation. Except as set forth in Schedule 4.2(j), there
is no action, suit, investigation or proceeding pending against AMHC or its
subsidiaries, or, to AMHC's knowledge, threatened against or affecting AMHC,
before any court or arbitrator or any governmental body, agency or official
relating to the transactions contemplated hereby or which, if determined or
resolved adversely to AMHC, may have, individually or in the aggregate, a
Material Adverse Effect on AMHC (as defined in Section 8.5).

                  (k) Employee Benefit Plans. Each employee benefit plan of AMHC
and its subsidiaries (and each related trust, insurance contract or fund) to the
knowledge of AMHC is being maintained and administered in compliance with its
terms and to the knowledge of AMHC, AMHC has complied in form and in operation
in all respects with the applicable requirements of all laws, regulations and
rulings, including but not limited to ERISA and the Code, and all amounts due
thereunder have been paid, except, in each case to the extent that any such
non-compliance would not, nor could reasonably be expected to result in a
Material Adverse Effect on AMHC (as defined in Section 8.5).

                  (l) Compliance With Laws. To the knowledge of AMHC, neither
AMHC nor any of its subsidiaries is in conflict with, or in default or violation
of any law, rule, regulation, order, judgment or decree applicable to AMHC or
any of its subsidiaries or by which AMHC or any of its subsidiaries or any of
their respective properties is bound or affected, in each case except for such
matters which do not have, nor could reasonably be expected to have, a Material
Adverse Effect (as defined in Section 8.5) on AMHC. To the knowledge of AMHC,
(i) no investigation or review by any governmental entity is pending or
threatened against AMHC or any of its subsidiaries, nor has any governmental
entity indicated an intention to conduct the same and (ii) there is no material
judgment, injunction, order or decree binding upon AMHC or any of its
subsidiaries, in each case except for such matters which do not have, nor could
reasonably be expected to have, a Material Adverse Effect (as defined in Section
8.5) on AMHC.

                  (m) Environmental Matters. Except as set forth in Schedule
4.2(m), to the knowledge of AMHC, each of AMHC and its subsidiaries is in
material compliance with all Environmental Laws, which compliance includes, but
is not limited to, the possession by AMHC or its subsidiaries of all permits and
other governmental authorizations required under applicable Environmental Laws,
and compliance with the terms and conditions thereof, except in each case any
such non-compliance which does not have, nor could reasonably be expected to
have, a Material Adverse Effect on AMHC (as defined in Section 8.5).

                                    Article V
                                    Covenants




                                      -11-
<PAGE>   12

         Section 5.1 Conduct of Business Prior to Closing. During the term of
this Agreement each of AMHC and AMH shall, and shall cause each of their
respective subsidiaries to, operate its business only in the ordinary course and
shall use all reasonable efforts to preserve intact its ongoing business, except
(i) the sale of property identified on Schedule 5.1 at the price and upon the
terms set forth on Schedule 5.1, (ii) as otherwise mutually agreed or, (iii) in
the case of AMHC and its subsidiaries, except for sales of assets with prior
approval of the board of directors of each of AMHC and AMH.

         Section 5.2 Best Efforts. Each of AMHC and AMH agrees to use its
reasonable best efforts to take or cause to be taken and to do or cause to be
done all such actions and things as shall be reasonably necessary or advisable,
or as shall be reasonably requested by the other party, in order to consummate
and make effective the Merger and the transactions contemplated hereby.

         Section 5.3 Securities Filings. Each of AMHC and AMH shall cooperate
and promptly prepare and file with the SEC and any applicable state agency, all
filings required under federal or state securities laws, and shall obtain all
"Blue Sky" permits or securities approvals required to carry out the Merger and
the transactions contemplated by this Agreement.

         Section 5.4 Members' and Stockholders' Approval. The Board of Directors
of AMHC shall recommend approval and adoption of the Plan, this Agreement and
the Merger by its members, and the Board of Directors of AMH shall recommend
approval and adoption of this Agreement and the Merger by its stockholders, and
each of AMHC and AMH shall use its reasonable best efforts to obtain the
approval and adoption of this Agreement and the Merger from its members and
stockholders, respectively, and otherwise comply with all legal requirements
applicable to the respective approvals required.

         Section 5.5 Indemnification. From and after the Effective Time, AMHC
will cause the Surviving Corporation to fulfill and honor in all respects the
indemnification obligations of AMH and AMHC pursuant to their respective
Articles of Incorporation, Bylaws and any indemnification agreements between AMH
and its directors and officers and AMHC and its directors and officers existing
prior to the date hereof. Until the sixth anniversary of the Effective Time,
AMHC shall cause the Surviving Corporation to maintain director's and officer's
liability insurance with respect to claims against the directors and officers of
AMHC and AMH arising from facts or events which occurred before the Effective
Time, which insurance shall contain at least the same coverage and amounts as
that coverage currently provided by AMHC or AMH, respectively, with respect to
its directors and officers.

         Section 5.6 Notification of Certain Matters. Each of AMHC and AMH will
give prompt notice to the other of the occurrence, or failure to occur, of any
event, which occurrence or failure to occur would be reasonably likely to cause
(a) any representation or warranty contained in this Agreement and made by it to
be untrue or inaccurate in any material respect at any time from the date of
this Agreement to the Effective Time such that the conditions set forth in
Section 6.2(a) or 6.3(a), as the case may be, would not be satisfied as a result
thereof, or (b) any material failure of AMHC or AMH, as the case may be, to
comply with or satisfy any covenant, condition or agreement to be complied with
or satisfied by it under this Agreement.



                                      -12-
<PAGE>   13

Notwithstanding the above, delivery of any notice pursuant to this section will
not limit or otherwise affect the remedies available hereunder to the party
receiving such notice.

         Section 5.7 Notices of Demand for Appraisal. AMH shall give AMHC (i)
prompt notice of any written demands for appraisal or any withdrawals of such
demands, and any other instruments served pursuant to IBCA and received by AMH
which relate to any such demand for appraisal and (ii) the opportunity to
participate in all negotiations and proceedings which take place prior to the
Effective Time with respect to demands for appraisal under IBCA. AMH shall not,
except with the prior written consent of AMHC or as may be required by
applicable law, voluntarily make any payment with respect to any demands for
appraisal of AMH Shares or offer to settle or settle any such demands.

         Section 5.8 Dividends. AMHC shall not permit its non-insurance
subsidiaries to declare, set aside or pay any dividends on, or make any other
distributions in respect of the capital stock of such subsidiaries, including,
without limitation, any repurchase of capital stock.

         Section 5.9 Modification of Plan. AMHC shall not modify or amend the
Plan, whether pursuant to Section 7.3 or 7.4 thereof or otherwise, in any manner
that adversely affects AMH or the stockholders of AMH (other than AMHC) in a
material manner.

         Section 5.10 Listing Application. AMHC shall promptly prepare and file
with the New York Stock Exchange or NASDAQ National Market listing applications
covering the AMHC Shares issuable in the Merger or upon exercise or conversion
of the Continuing Common Stock Rights and shall use its reasonable best efforts
to obtain, prior to the Effective Time, approval for listing of such Common
Stock, subject only to official notice of issuance.

         Section 5.11 Actions Relating to Continuing Common Stock Rights. AMHC
shall take all actions reasonably necessary to assume the Continuing Common
Stock Rights, employee benefit plans of AMH, execute supplemental indentures
where necessary and otherwise assume the obligations of AMH in accordance with
this Agreement and the IBCA.

         Section 5.12 Schedules. From time to time prior to the Effective Time,
the parties to this Agreement shall promptly supplement and amend the Schedules
to this Agreement with respect to any matter, condition or occurrence hereafter
arising which, if existing or occurring at the date of this Agreement, would
have been required to be set forth or described in the Schedules at such time.
Unless waived by the other party hereto, which waiver shall not be unreasonably
withheld, no supplement or amendment shall be deemed to cure any breach of any
representation or warranty made in this Agreement or have any effect for the
purpose of determining satisfaction of the conditions set forth in Section
6.2(a) or Section 6.3(a).

                                   Article VI
                      Conditions to Consummation of Merger

         Section 6.1 Conditions to Obligations of Each Party. The respective
obligation of each of AMHC and AMH to effect the Merger shall be subject to the
satisfaction at or prior to the Effective Time of the following conditions:



                                      -13-
<PAGE>   14

                  (a) AMHC Approvals. The Plan, this Agreement and transactions
contemplated hereby shall have been approved and adopted by the requisite vote
of the members of AMHC in accordance with and to the extent required by the
Plan, Articles of Incorporation of AMHC or applicable laws;

                  (b) AMH Approvals. This Agreement and transactions
contemplated hereby shall have been approved and adopted by the requisite vote
of each class of the stockholders of AMH in accordance with and to the extent
required by the Articles of Incorporation of AMH or applicable laws;

                  (c) No Injunctions. No preliminary or permanent injunction or
other order of any federal or state court in the United States which prohibits
the consummation of the Merger shall have been issued and remain in effect;

                  (d) Securities Filings. All required securities filings shall
have become effective and shall be effective at the Effective Time, and no stop
order suspending effectiveness of such filings shall have been issued, and no
action, suit, proceeding or investigation by the SEC or any state securities
commission to suspend the effectiveness thereof shall have been initiated and be
continuing, or, to the knowledge of AMHC or AMH, threatened, and all necessary
approvals under state securities laws relating to the issuance or trading of
AMHC Shares to be issued in connection with the Merger shall have been received;

                  (e) Regulatory Approvals. Approval of any necessary regulatory
bodies shall have been obtained and be in effect, except for approvals which the
failure to obtain would not, individually or in the aggregate, in the judgment
of AMHC and AMH, be reasonably expected to result in a Material Adverse Effect
(as defined in Section 8.5) on AMHC, AMH or the Surviving Corporation;

                  (f) Listing. The AMHC Shares issuable in the Merger and in
connection with the exercise of Continuing Common Stock Rights shall have been
approved for listing on the New York Stock Exchange, or, if mutually agreed, on
another exchange or quoted in the automated quotation system of a registered
securities association, subject only to official notice of issuance;

                  (g) Litigation. No order, judgment or decree shall be
outstanding against a party hereto or a third party that would have the effect
of imposing materially adverse conditions deemed to be unreasonable by AMHC or
AMH to, or preventing completion of, the Merger and no suit, action or other
proceeding shall be pending before any court or governmental entity in which it
is sought to restrain or prohibit the Merger or obtain other substantial
monetary or other relief against one or more parties hereto in connection with
this Agreement or the Plan and which AMHC or AMH determines in good faith, based
upon the advice of their respective counsel, makes it inadvisable to proceed
with the Merger because any such suit, action or proceeding has a significant
potential to be resolved in a way so as to deprive the party electing not to
proceed of any of the material benefits to it of the Merger;

                  (h) Non-Governmental Consents. All consents or approvals of
all persons, other than the Iowa Commissioner, Kansas Commissioner, required
securities or broker-dealer




                                      -14-
<PAGE>   15

approvals, or other regulatory bodies, and supplements to any outstanding
indentures entered into by AMHC or AMH, required for or in connection with the
execution, delivery and performance of this Agreement and the consummation of
the Merger shall have been obtained and be in full force and effect, unless the
failure to obtain any such consent or approval is not in the judgment of AMHC
and AMH reasonably likely to have, individually or in the aggregate, a Material
Adverse Effect (as defined in Section 8.5) on AMHC, AMH or the Surviving
Corporation;

                  (i) Effectiveness of Plan. All conditions precedent to the
effectiveness of the Plan (including, without limitation, receipt of the opinion
of Caplin & Drysdale, Chartered, special tax counsel referenced in the Plan),
except for effectiveness of the Merger, shall have been satisfied or waived,
subject to the extent required by law to the approval of the Iowa Commissioner;

                  (j) Tax Opinions. Each of AMHC and AMH shall have received a
copy addressed to it of the opinion of Caplin & Drysdale, Chartered, referenced
in the Plan. In addition, each of AMHC and AMH shall have received an opinion of
counsel or accountant or other confirmation reasonably satisfactory to AMHC and
AMH, to the effect that the transactions contemplated by this Agreement do not
result in the imposition of an entity-level state tax; and

                  (k) Insurance. AMHC shall have purchased (i) single premium
environmental liability insurance with a ten year term in an amount of $50
million per event and in the aggregate and with a retention of $500,000 per
event including, without limitation, coverage for items set forth in Schedule
4.2(m), and (ii) representation and warranty insurance in an amount and upon
such terms upon which AMHC and AMH mutually agree.

         Section 6.2 Additional Conditions to Obligations of AMHC. The
obligation of AMHC to consummate and effect the Merger shall be subject to the
satisfaction at or prior to the Effective time of each of the following
conditions, any of which may be waived, in writing, exclusively by AMHC, in its
sole discretion.

                  (a) Representations and Warranties. The representations and
warranties of AMH contained in this Agreement shall have been true and correct
in all material respects as of the date of this Agreement. In addition, the
representations and warranties of AMH contained in this Agreement shall be true
and correct in all material respects on and as of the Effective Time except for
changes contemplated by this Agreement, with the same force and effect as if
made on and as of the Effective Time, except in such cases where the failure to
be so true and correct would not have a Material Adverse Effect (as defined in
Section 8.5) on AMH.

                  (b) Agreements and Covenants. AMH shall have performed or
complied in all material respects with all agreements and covenants required by
this Agreement to be performed or complied with by them at or prior to the
Effective Time.

                  (c) Material Adverse Effect. No Material Adverse Effect (as
defined in Section 8.5) with respect to AMH shall have occurred since the date
of this Agreement.



                                      -15-
<PAGE>   16

         Section 6.3 Additional Conditions to the Obligations of AMH. The
obligations of AMH to consummate and effect the Merger shall be subject to the
satisfaction at or prior to the Effective Time of each of the following
conditions, any of which may be waived, in writing, exclusively by AMH, in its
sole discretion.

                  (a) Representations and Warranties. The representations and
warranties of AMHC contained in this Agreement shall have been true and correct
in all material respects as of the date of this Agreement. In addition, the
representations and warranties of AMHC contained in this Agreement shall be true
and correct in all material respects on and as of the Effective Time except for
changes contemplated by this Agreement, with the same force and effect as if
made on and as of the Effective Time, except in such cases where the failure to
be so true and correct would not have a Material Adverse Effect (as defined in
Section 8.5) on AMHC.

                  (b) Agreements and Covenants. AMHC shall have performed or
complied in all material respects with all agreements and covenants required by
this Agreement to be performed or complied with by it at or prior to the
Effective Time.

                  (c) Material Adverse Effect. No Material Adverse Effect (as
defined in Section 8.5) with respect to AMHC shall have occurred since the date
of this Agreement.

                  (d) Corporate Opinion. AMH shall have received an opinion
dated as of the date of Closing of Belin Lamson McCormick Zumbach Flynn, A
Professional Corporation, corporate counsel to AMHC, in form and substance
reasonably satisfactory to it, to the effect that the AMHC Shares issuable
pursuant to the Merger are duly authorized, validly issued, fully paid and
non-assessable and with respect to such other matters as AMH may reasonably
request.

                                   Article VII
                        Termination, Amendment and Waiver

         Section 7.1 Termination. This Agreement may be terminated at any time
prior to the Effective Time, whether before or after approval by the
stockholders of AMH and members of AMHC:

                  (a) by mutual written consent duly authorized by the Board of
Directors of each of AMH and AMHC;

                  (b) by AMHC if the approval of the stockholders of AMH
contemplated by this Agreement shall not have been obtained by reason of the
failure to obtain the required vote at a duly held meeting of stockholders;

                  (c) by AMH if the approval of the members of AMHC contemplated
by this Agreement shall not have been obtained by reason of the failure to
obtain the required vote at a duly held meeting of members;

                  (d) by AMHC, upon a breach of any representation, warranty,
covenant or agreement on the part of AMH set forth in this Agreement, or if any
representation or warranty of AMH shall have become untrue, in either case such
that the conditions set forth in Section 6.2(a)



                                      -16-
<PAGE>   17

or Section 6.2(b) would not be satisfied as of the time of such breach or as of
the time such representation or warranty shall have become untrue, provided,
that if such inaccuracy in AMH's representations and warranties or breach by AMH
is curable by AMH through the exercise of its commercially reasonable efforts,
then AMHC may not terminate this Agreement under this Section 7.1(d) provided
AMH continues to exercise such commercially reasonable efforts to cure such
breach; or

                  (e) by AMH, upon a breach of any representation, warranty,
covenant or agreement on the part of AMHC set forth in this Agreement, or if any
representation or warranty of AMHC shall have become untrue, in either case such
that the conditions set forth in Section 6.3(a) or Section 6.3(b) would not be
satisfied as of the time of such breach or as of the time such representation or
warranty shall have become untrue, provided, that if such inaccuracy in AMHC's
representations and warranties or breach by AMHC is curable by AMHC through the
exercise of its commercially reasonable efforts, then AMH may not terminate this
Agreement under this Section 7.1(e) provided AMHC continues to exercise such
commercially reasonable efforts to cure such breach.

         Section 7.2 Effect of Termination; Exclusive Remedy. If this Agreement
is validly terminated pursuant to Section 7.1 hereof, this Agreement shall
forthwith become null and void, and there will be no liability on the part of
AMHC, AMH or any of their respective affiliates, officers, directors, employees,
agents, consultants or other representatives with respect to this Agreement or
the matters contemplated hereby. Termination shall be the sole and exclusive
remedy available to a party hereunder, and to the full extent permitted by law,
each party hereby waives all rights to remedies other than termination of this
Agreement.

         Section 7.3 Amendment. This Agreement may be amended by the parties
hereto at any time before or after any required approval of matters presented in
connection with the Merger by the stockholders of AMH and members of AMHC and,
to the extent required by law, subject to the approval of the Iowa Commissioner;
provided, however, that after any such approval, there shall not be made without
approval of the applicable stockholders and members any amendment that by law or
governing document is required to be submitted to the stockholders or members of
any of the parties hereto for approval. This Agreement may not be amended except
by an instrument in writing signed on behalf of each of the parties hereto.

         Section 7.4 Waiver. At any time prior to the Effective Time, the
parties hereto may (a) extend the time for the performance of any of the
obligations or other acts of the other party hereto, or (b) waive compliance
with any of the agreements or conditions contained herein. Any agreement on the
part of a party hereto to any such extension or waiver shall be valid only if
set forth in an instrument in writing signed on behalf of such party.

                                  Article VIII
                   General Provisions; Post-Closing Covenants

         Section 8.1 Entire Agreement; No Assignment. This Agreement (including
any Exhibits and Schedules, and other documents and instruments referred to
herein) (a) constitutes the entire agreement and supersedes all other prior
agreements and understandings, both written




                                      -17-
<PAGE>   18

and oral among the parties or any of them, with respect to the merger of AMH
with and into AMHC; (b) is not intended to confer upon any other person any
rights or remedies hereunder, except that the current and former directors and
officers of AMH are intended by the parties to this Agreement to be third party
beneficiaries of Section 5.5 of this Agreement; and (c) shall not be assigned by
operation of law or otherwise.

         Section 8.2 Representations, Warranties and Covenants. (a) The
representations and warranties of AMHC and AMH contained in this Agreement shall
terminate at the Effective Time, and only the covenants that by their terms
survive the Effective Time shall survive the Effective Time.

         (b) Notwithstanding any other provision of this Agreement, any
representation, warranty or covenant made by AMHC with respect to its
subsidiaries shall not for purposes of this Agreement include AMH and/or its
subsidiaries.

         Section 8.3 Governing Law. This Agreement shall be governed by and
construed in accordance with the laws of the State of Iowa without giving effect
to the provisions thereof relating to conflicts of law.

         Section 8.4 Additional Actions. If, at any time after the Effective
Time, the Surviving Corporation shall consider that any further assignments or
assurances in law or any other acts are necessary or desirable to (i) vest,
perfect or confirm, of record or otherwise, in the Surviving Corporation its
right, title or interest in, to or under any of the rights, properties or assets
of AMH acquired or to be acquired by the Surviving Corporation as a result of,
or in connection with, the Merger, or (ii) otherwise carry out the purposes of
this Agreement, AMH and its proper officers and directors shall be deemed hereby
to have granted to the Surviving Corporation an irrevocable power of attorney
coupled with an interest to execute and deliver all such proper deeds,
assignments and assurances in law and to do all acts necessary or proper to
vest, perfect or confirm title to and possession of such rights, properties or
assets in the Surviving Corporation and otherwise to carry out the purposes of
this Agreement; and the proper officers and directors of the Surviving
Corporation are fully authorized in the name of AMH or otherwise to take any and
all such action.

         Section 8.5 Definition of Material Adverse Effect; Person; Knowledge.
For the purposes of this Agreement, the term "Material Adverse Effect," with
respect to any Person, shall mean any change, event or effect that is material
and adverse to the business, assets, financial condition, results of operations
or prospects of such Person and its subsidiaries taken as a whole (except for
those changes, events and effects that are directly caused by (i) conditions
affecting the United States economy as a whole; or (ii) conditions affecting
either the insurance or annuity industry, in either such case as a whole, which
conditions (in the case of clause (i) or (ii)) do not affect such Person and its
subsidiaries taken as a whole in a disproportionate manner; or (iii) any adverse
effect on a Person and its subsidiaries taken as a whole, or the operations of
such Person and its subsidiaries taken as a whole, where such effect is
primarily attributable to the transactions contemplated by this Agreement or the
pendency or announcement of the Merger). For purposes of this Agreement,
"Person" shall mean any corporation, partnership or other business entity.
References herein to the "knowledge of," "best knowledge of," "know" and
variations thereof of



                                      -18-
<PAGE>   19

a Person, mean the actual knowledge of the Chairman of the Board, Chief
Executive Officer, Senior Vice President, Chief Financial Officer and Treasurer,
Senior Vice President and Secretary or Senior Vice President and General Counsel
of such Person. References to "subsidiaries" herein shall not include AMH when
the "Person" is AMHC.

         Section 8.6 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
shall constitute one and the same agreement.

         IN WITNESS WHEREOF, each of AMH and AMHC has caused this Agreement to
be executed on its behalf by its officers thereunto duly authorized, all as of
the date first above written.

                                 AMERICAN MUTUAL HOLDING COMPANY



                                 By: s/ Roger K. Brooks
                                     ---------------------------------------
                                     Name:  Roger K. Brooks
                                     Title:   Chairman, President & CEO

                                 AMERUS LIFE HOLDINGS, INC.




                                 By: s/ Michael G. Fraizer
                                     ---------------------------------------
                                     Name:  Michael G. Fraizer
                                     Title: Senior Vice President & CFO



                                      -19-