<PAGE>
 
                                                                   Exhibit 10.41

 
                             EMPLOYMENT AGREEMENT
                             --------------------


     THIS EMPLOYMENT AGREEMENT (the "Agreement") is made as of December 1, 1996
between ATLAS CORPORATION, a Delaware corporation ("Employer"), and Gregg B.
Shafter of Employer ("Executive").

     Employer and Executive agree as follows:

     1.   EMPLOYMENT. In accordance with the terms and conditions of this
Agreement, Employer agrees to employ Executive as an officer of Employer
commencing June 1, 1995, and continuing until that employment is terminated (a)
by either Employer or Executive or (b) by reason of Executive's normal
retirement in accordance with Employer's retirement programs applicable to
Executive at the time of his retirement ("Executive's Retirement"). Executive
accepts that employment and agrees to perform the duties associated therewith.
Subject to the terms and conditions of this Agreement, Executive's employment by
Employer may be terminated at any time by either Executive or Employer by 10
days prior written notice to that effect.

     2.   DUTIES. As long as Executive is employed by Employer hereunder,
Executive shall be subject to the direction of and be responsible to the
President of Employer or his designee with respect to the performance of his
duties hereunder, shall report to the President of Employer in that connection
at such times and in such detail as the President of Employer may require and
shall devote his full business time, attention, skill and efforts to the
business and affairs of Employer.

     3.   SALARY. As compensation for the services to be furnished by Executive
to Employer hereunder, as long as Executive is employed by Employer hereunder,
Employer shall pay Executive a salary at a minimum annual rate of $85,000
payable in accordance with Employer's standard payroll policies applicable to
officers.

     4.   BASIC EMPLOYEE BENEFIT PLANS AND PROGRAMS. As long as Executive is
employed by employer hereunder, Executive shall be entitled to participate in
all regular and key employee benefit plans and programs which are or may be made
available by Employer for its officers.

     5.   EXPENSES. Employer shall provide for the payment of, or reimbursement
of Executive for, all travel and other out-of-pocket expenses reasonably
incurred by Executive in the performance of his duties hereunder.

<PAGE>
 
     6.   TERMINATION.

          6.1  Certain Definitions.  As used in this Section 6:

               (a)  "Board" means the Board of Directors of Employer.

               (b)  "Cause" means, and is limited to, (i) the conviction of
Executive for a felony or misdemeanor (other than minor motor vehicle and
similar offenses) under the laws of the United States or any state thereof; (ii)
any material breach by Executive of this Agreement or the failure of Executive
to comply with any lawful directive of the Chairman of the Board or to follow
Employer policies; (iii) dishonesty, gross negligence or malfeasance by
Executive in the performance of his duties hereunder (other than the mere
failure to achieve financial results); (iv) Executives habitual insobriety or
substance abuse; (v) unlawful appropriation by Executive of a corporate
opportunity of Employer or any of its affiliates; or (vi) the Executives taking
or omission to take any other action or actions in the performance of his duties
hereunder or the making of any statement which, in the good faith determination
of the Board, is disruptive or damaging to the business, reputation, operations,
prospects or business relations of Employer or its affiliates of which achieves
general notoriety with respect to conduct or alleged conduct by Executive which
is illegal, immoral or scandalous.

               (c)  "Change of Control Event" means any one of the following:
(i) Continuing Directors no longer constitute at least two thirds of the
Directors constituting the Board; (ii) any person or group (as defined in Rule
13d-5 under the Securities Exchange Act of 1934), together with its affiliates,
other than Mackenzie Financial Corporation, M.I.M. Holdings Limited or H. R.
Shipes (in each case, together with its affiliates), becomes the beneficial
owner, directly or indirectly, of 15% or more of Employer's then outstanding
Common Stock or 15% or more of the voting power of Employer's then outstanding
securities entitled generally to vote for the election of Directors, provided
that the foregoing circumstances shall not constitute a Change of Control Event
if such beneficial owner is Employer, any subsidiary of Employer, any employee
benefit plan or employee stock plan of Employer or of any subsidiary of
Employer; and provided further that, notwithstanding the foregoing, a Change of
Control Event shall be deemed to occur if Mackenzie Financial Corporation, and
its affiliates, M.I.M. Holdings Limited, and its affiliates, or H. R. Shipes and
his affiliates, shall acquire 25% or more of the Employer's then outstanding
Common Stock or the voting power of the Employer's then outstanding securities
entitled generally to vote for the election of Directors; (iii) the approval by
Employer's stockholders of the merger or consolidation of Employer with any
other corporation, the sale of substantially all of Employer's assets or the
liquidation or dissolution of Employer, unless, in the case of a merger or
consolidation, the Continuing Directors in office immediately prior to such
merger or consolidation constitute at least two thirds of the directors
constituting the board of directors of the surviving corporation of such merger
or consolidation and any parent (as such term is defined in Rule 12b-2 under the
Securities Exchange Act of 1934) of such corporation; or (iv) at least two
thirds of the Continuing Directors in office immediately prior to any other
action taken or proposed to be taken by Employer's stockholders or by the Board
determines that such action constitutes, or that such

                                       2
<PAGE>
 
proposed action, if taken, would constitute, a change of control of Employer
and such action is taken.

               (d)  "Continuing Director" means any person who (i) is a Director
on the date of this Agreement; (ii) was designated before such person's initial
election as a Director as a Continuing Director by a majority of the Continuing
Directors; or (iii) has been a Director for at least two years after the
occurrence of one or more Change of Control Events.

               (e)  "Director" means a member of the Board.

               (f)  "Disability" means, as applied to Executive, that (i) he has
been so incapacitated by bodily injury or disease as to be unable to perform the
duties contemplated to be performed by him hereunder, (ii) the incapacity shall
have continued for a period of three consecutive months and (iii) the incapacity
will, in the opinion of a qualified physician acceptable to Employer, be
permanent and continuous for a period of at least one year.

               (g)  "Good Reason" means (i) without Executive's written consent
(A) (1) the assignment to Executive of any duties and responsibilities, or any
limitation of Executive's duties and responsibilities, if such assignment or
limitation is materially inconsistent with Executive's positions, duties,
responsibilities and status as an executive of Employer or (2) any removal of
Executive from, or any failure to reelect Executive to, any of Executive's
positions with Employer except for Cause or as a result of the death or
Disability of Executive, and (B) the continuance thereof for a period of 20 days
after written notice thereof to Employer from Executive; (ii) any failure by
Employer to pay, or any reduction by Employer of, the salary payable to
Executive under Section 3 of this Agreement; (iii) any failure by Employer (A)
to continue to provide Executive with the opportunity to participate, on terms
no less favorable than those in effect immediately prior to a Change of Control
Event, in any benefit plan or program in which Executive was participating
immediately prior to the Change of Control Event, or their equivalent, or (B) to
provide Executive with all other fringe benefits, or their equivalent, from time
to time in effect for the benefit of any of Employer's salaried employees; (iv)
the failure by Employer to obtain the specific assumption of this Agreement by a
successor or assign of Employer or by any person acquiring substantially all of
Employer's assets; or (v) any material breach by Employer of any provision of
this Agreement.

               6.2  Compensation of Executive in the Event of Termination of
Executive's Employment Hereunder.

                    (a)  In the event of Executive's Disability, Executive's
employment by Employer hereunder may be terminated by Employer upon written
notice from Employer to Executive which shall specify a date not less than 30
days from the date of such notice as the date on which such termination shall
become effective. If Executive's employment by Employer hereunder is terminated
because of Executive's Disability or death, Executive, or his heirs, executors
or administrators if termination is because of Executive's death, shall be
entitled to

                                       3
<PAGE>
 
receive the salary payable to Executive under Section 3 until the date on which
the termination occurs.

               (b)  (i) Executive shall be entitled to compensation as specified
in Section 6.2(b)(ii) and (iii) if (A) Employer terminates Executive's
employment hereunder without Cause either prior to 3 months before a Change of
Control Event or more than two years after the last Change of Control Event, or
(B) Executive voluntarily terminates his employment hereunder with Good Reason
either prior to 3 months before a Change of Control Event or more than two years
after the last Change of Control Event. (ii) Prior to the 30th day following the
date of such termination Employer shall pay Executive (A) an amount equal to 
one-twelfth of such Executive's annual rate of base salary that is in effect on
the date of termination multiplied by the number of full years of employment by
the Company, provided that in no event shall such amount be less than one-half
of the amount of Executive's annual base salary in effect on the date of
termination, and (B) all amounts which had accrued but were not paid prior to
such termination for personal services actually rendered before the termination.
(iii) As soon as practicable following the date of such termination, or at such
later date as Executive may validly elect, Employer shall pay Executive all
amounts payable under then existing employee benefit plans and programs.
Notwithstanding the foregoing, if the sum of all of the payments to Executive
whether under this Agreement or otherwise (but excluding any payments which need
not be included in determining if a "parachute payment" has been made within the
meaning of Internal Revenue Code (the "Code") (S) 280G(b)(2)) exceeds the
product of multiplying the Base Amount times 2.99, then such payments hereunder
shall be reduced by the amount of such excess. For purposes of this Agreement,
the term Base Amount is defined in Code (S) 280G(b)(3) and the Treasury
Regulations promulgated thereunder, calculated as of the date required under the
Code.

               (c)  (i) Executive shall be entitled to compensation as specified
in Section 6.2(c)(ii) and (iii) if (A) Employer terminates Executive's
employment hereunder without Cause either (1) within 3 months prior to a Change
of Control Event or (2) upon or after a Change of Control Event but within two
years after the date of that Change of Control Event, or (B) Executive
voluntarily terminates his employment hereunder with Good Reason either (1)
within 3 months prior to a Change of Control Event or (2) upon or after a Change
of Control Event but within two years after the date of that Change of Control
Event. (ii) Prior to the 30th day following the date of such termination
Employer shall pay Executive (A) the amount which equals the Executive's annual
rate of base salary that is in effect on the date of termination, and (B) all
amounts which had accrued but were not paid prior to such termination for
personal services actually rendered before the termination. (iii) As soon as
practicable following the date of such termination, or at such later date as
Executive may validly elect, Employer shall pay Executive all amounts payable
under then existing employee benefit plans and programs. Notwithstanding the
foregoing, if the sum of all of the payments to Executive whether under this
Agreement or otherwise (but excluding any payments which need not be included in
determining if a "parachute payment" has been made within the meaning of Code
(S) 280G(b)(2)) exceeds the Base Amount times 2.99, then such payments hereunder
shall be reduced by the amount of such excess.

                                       4
<PAGE>
 
               (d)  If Executive's employment hereunder is terminated by
Employer or by Executive under any circumstances other than as set forth in
Section 6.2(a), 6.2(b), or 6.2(c), all payments required by this Agreement shall
cease and the termination shall relieve Employer of its obligations to make any
further payments under this Agreement except payments under the employee benefit
plans and programs and payments of amounts which had accrued but were not yet
paid prior to the termination.

     7.   CONFIDENTIAL INFORMATION AND TRADE SECRETS. Executive acknowledges
that all information possessed by him relating to activities of Employer that is
of a secret or confidential nature, including without limitation financial
information, exploration, mining and milling information, lists of customers,
technical and production know-how, developments, inventions, processes and
administrative procedures, is the property of Employer, and as long as Executive
is employed by Employer hereunder, and for a period of two years thereafter,
Executive shall not use any such information for the benefit of anyone other
than Employer or disclose any such information to others except in the course of
Employer's business.

     8.   PAYMENT TO ESTATE OR BENEFICIARY. If Executive dies before any
payments required to be paid by Employer to Executive hereunder have been paid,
Employer shall make all such payments to the beneficiary or beneficiaries
designated by Executive in a written notice previously delivered by Executive or
Employer or, in the absence of such a notice, to Executive's estate.

     9.   ARBITRATION. Any and all disputes arising under or relating to this
Agreement shall be subject to mandatory binding arbitration in Denver, Colorado,
before the American Arbitration Association in accordance with its Commercial
Arbitration Rules. Discovery shall be allowed but subject to the limits and
procedures set forth in Rule 26.1 of the Colorado Rules of Civil Procedure. The
prevailing party in any such arbitration proceeding shall be entitled to an
award of his or its reasonable costs and attorney fees.

     10.  BINDING EFFECT; SUCCESSORS, ASSIGNMENT. Subject to the provisions of
this Section 10, this Agreement shall be binding upon, inure to the benefit of
and be enforceable by Employer and Executive and their respective heirs, legal
representatives, successors and assigns. If Employer shall be merged into or
consolidated with another entity, the provisions of this Agreement shall be
binding upon and inure to the benefit of the entity surviving such merger or
resulting from such consolidation.

     11.  GOVERNING LAW. This Agreement shall be governed by and construed in
accordance with the laws of the State of Colorado applicable to contracts made
and to be performed therein.

                                       5
<PAGE>
 
     12.  NOTICE. Any notice required to be given hereunder shall be in writing
and delivered by certified mail, return receipt requested, addressed:

          To Employer at:

               Republic Plaza
               370 Seventeenth Street
               Suite 3050
               Denver, Colorado  80202

          To Executive at:

               Republic Plaza
               370 Seventeenth Street
               Suite 3050
               Denver, Colorado  80202

or in either case to such other address as may be specified in a written notice
given as provided above.

     13.  ENTIRE AGREEMENT; AMENDMENT. This Agreement represents the entire
agreement of Employer and Executive with respect to the subject matter hereof
and shall supersede any and all previous agreements, arrangements and
understandings between Employer and Executive in that regard. This Agreement may
be amended only by the written agreement of Employer and Executive.

                                            ATLAS CORPORATION


                                            By: /s/  Mario Caron
                                                -----------------------
                                                Chief Executive Officer



                                            EXECUTIVE

                                            By: /s/  Gregg B. Shafter
                                                -----------------------
                                                Gregg B. Shafter


                                       6