Exhibit 4.5


 


ATLANTIC POWER CORPORATION


 


AND


 


COMPUTERSHARE TRUST COMPANY OF CANADA


 


 


FIRST SUPPLEMENTAL INDENTURE


 


TO TRUST INDENTURE DATED DECEMBER 17, 2009


 


 


PROVIDING FOR THE ISSUE OF SERIES B CONVERTIBLE UNSECURED
SUBORDINATED DEBENTURES


 


 


SEPTEMBER ·, 2010


 

















 


TABLE OF CONTENTS


 


	
  ARTICLE 1
  INTERPRETATION

  	
  2

  
	
  1.1

  	
  Interpretation

  	
  2

  
	
  1.2

  	
  Additional
  Definitions

  	
  2

  
	
  1.3

  	
  Headings
  Etc.

  	
  2

  
	
  1.4

  	
  Day
  not a Business Day

  	
  3

  
	
  1.5

  	
  Applicable
  Law

  	
  3

  
	
  1.6

  	
  Monetary
  References

  	
  3

  
	
  1.7

  	
  Invalidity/Severability

  	
  3

  
	
  1.8

  	
  Time
  of Essence

  	
  3

  
	
  1.9

  	
  Language

  	
  3

  
	
  1.10

  	
  Successors
  and Assigns

  	
  3

  
	
  1.11

  	
  Benefits
  of Supplemental Indenture

  	
  4

  
	
  ARTICLE 2
  TERMS OF SERIES B DEBENTURES

  	
  4

  
	
  2.1

  	
  Terms
  of Series B Debentures

  	
  4

  
	
  2.2

  	
  Delivery

  	
  13

  
	
  2.3

  	
  Legends
  and Certification

  	
  13

  
	
  ARTICLE 3
  CONFIRMATION OF TRUST INDENTURE

  	
  13

  
	
  3.1

  	
  Confirmation
  of Trust Indenture

  	
  13

  
	
  ARTICLE 4
  ACCEPTANCE OF TRUST BY DEBENTURE TRUSTEE

  	
  14

  
	
  4.1

  	
  Acceptance
  of Trust

  	
  14

  
	
  ARTICLE 5
  EXECUTION AND FORMAL DATE

  	
  14

  
	
  5.1

  	
  Execution

  	
  14

  
	
  5.2

  	
  Formal
  Date

  	
  14

  



SCHEDULE “A” FORM OF
SERIES B DEBENTURES


SCHEDULE “B” FORM OF REDEMPTION NOTICE


SCHEDULE “C” FORM OF MATURITY NOTICE


SCHEDULE “D” FORM OF NOTICE OF CONVERSION


SCHEDULE “E” FORM OF NOTICE OF PUT EXERCISE


 


i

















 


ATLANTIC
POWER CORPORATION

·% SERIES B CONVERTIBLE UNSECURED SUBORDINATED DEBENTURES DUE 20·


 


FIRST
SUPPLEMENTAL INDENTURE


 


This First Supplemental
Indenture is made as of the · day of September, 2010.


 


B E T W E E N:


 


ATLANTIC POWER CORPORATION, a corporation continued under the laws of the
Province of British Columbia


 


(the “Company”)


 


- and -


 


COMPUTERSHARE
TRUST COMPANY OF CANADA, a trust company authorized to carry on business in
all of the provinces and territories of Canada


 


(the “Debenture Trustee”)


 


WHEREAS:


 


A.                                   By a Trust Indenture made as
of December 17, 2009 between the Company and the Debenture Trustee (the “Trust Indenture”), provision was made for the issuance of
debentures in one or more series, unlimited as to aggregate principal amount
but issuable only upon and subject to the conditions and limitations therein
set forth;


 


B.                                     Pursuant to an underwriting
agreement dated September ·, 2010 (the “Underwriting Agreement”) among the Company, BMO Nesbitt
Burns Inc. and certain other parties, the Company has agreed to create and
issue pursuant to the Trust Indenture and this first supplemental indenture to
the Trust Indenture (the “Supplemental  Indenture”), a series of debentures in aggregate principal
amount of up to $· to be designated as the “·% Series B Convertible
Unsecured Subordinated Debentures due ·“ (the “Series B
Debentures”) comprised of $· principal amount of Series B
Debentures to be issued contemporaneously herewith and up to $· principal amount of Series B
Debentures to be issued under the Over-Allotment Option (as defined below);


 


C.                                     When certified by the
Debenture Trustee and issued as provided in this Supplemental Indenture, all
necessary steps in relation to the Company will have been duly enacted, passed
and/or confirmed and other proceedings taken and conditions complied with to
make the creation and issue of the Series B Debentures proposed to be
issued hereunder legal, valid and binding on the Company in accordance with the
laws relating to the Company;


 


D.                                    This Supplemental Indenture is
hereinafter sometimes referred to as the “First Supplemental Indenture”; and


 

















 


E.                                      The foregoing recitals are
made as representations and statements of fact by the Company and not by the
Debenture Trustee;


 


NOW THEREFORE it is hereby covenanted,
agreed and declared as follows:


 


ARTICLE 1

INTERPRETATION


 


1.1                               Interpretation


 


This First Supplemental
Indenture is supplemental to the Trust Indenture and shall be read in
conjunction therewith.  Except only
insofar as the Trust Indenture may be inconsistent with the express provisions
of this First Supplemental Indenture, in which case the terms of this First
Supplemental Indenture shall govern and supersede those contained in the Trust
Indenture only to the extent of such inconsistency, this First Supplemental
Indenture shall henceforth have effect so far as practicable as if all the
provisions of the Trust Indenture and this First Supplemental Indenture were
contained in one instrument.  The
expressions used in this First Supplemental Indenture and in the Series B
Debentures that are defined in the Trust Indenture shall, except as otherwise
provided herein, have the respective meanings ascribed to them in the Trust
Indenture.  Unless otherwise stated, any
reference in this First Supplemental Indenture to an Article, Section or
Schedule shall be interpreted as a reference to the stated Article, Section of
or Schedule to, this First Supplemental Indenture.


 


1.2                               Additional Definitions


 


In this First
Supplemental Indenture and in the Series B Debentures, unless there is
something in the subject matter or context inconsistent therewith, the
expressions following shall have the following meanings, namely:


 


“2010
Offering”  means the
public offering under a Canadian short form prospectus dated September ·, 2010 and a U.S. prospectus
dated September ·, 2010 of $· aggregate principal amount of
Series B Debentures and up to an additional $· principal amount of Series B
Debentures pursuant to the Over-Allotment Option.


 


“Maturity
Date” means ·.


 


“Over
Allotment Option” means the option granted to the Underwriters to
purchase up to an additional $· aggregate principal amount of
Series B Debentures upon exercise of such option at any time or from time
to time until 30 days after the date hereof.


 


“Underwriters”
means BMO Nesbitt Burns Inc., ·, · and ·.


 


1.3                               Headings Etc.


 


The division of this
First Supplemental Indenture into Articles and Sections, the provision of a
Table of Contents and the insertion of headings are for convenience of
reference only and shall not affect the construction or interpretation of this
First Supplemental Indenture or of the Series B Debentures.


 


2

















 


1.4                               Day not a Business Day


 


In the event that any
day on which any action required to be taken hereunder is not a Business Day,
then such action shall be required to be taken on or before the requisite time
on the next succeeding day that is a Business Day.


 


1.5                               Applicable Law


 


This First Supplemental
Indenture and the Series B Debentures shall be construed in accordance
with the laws of the Province of Ontario and the laws of Canada applicable
therein and shall be treated in all respects as Ontario contracts.  The Company hereby irrevocably attorns to the
jurisdiction of the courts of the Province of Ontario.


 


1.6                               Monetary References


 


Whenever any amounts of
money are referred to herein, such amounts shall be deemed to be in lawful
money of Canada unless otherwise expressed.


 


1.7                               Invalidity/Severability


 


In case any provision
in this Supplemental Indenture or in the Series B Debentures shall be
invalid, illegal, prohibited or unenforceable, such provision shall be deemed
to be severed herefrom or therefrom and shall be ineffective only to the extent
of such prohibition or unenforceability. 
The validity, legality and enforceability of the remaining provisions
shall not in any way be affected, prejudiced or impaired thereby.


 


1.8                               Time of Essence


 


Time shall be of the
essence of this Supplemental Indenture.


 


1.9                               Language


 


Each of the parties
hereto hereby acknowledges that it has consented to and requested that this
Supplemental Indenture and all documents relating thereto, including, without
limiting the generality of the foregoing, the form of Debenture attached hereto
as Schedule A, be drawn up in the English language only.


 


Les parties aux présents
reconnaissent avoir accepté et demandé que le présent acte de fiducie et tous
les documents s’y rapportant, y compris, sans restreindre la portée générale de
ce qui précède, le formulaire de débenture joint aux présents à titre d’annexe
A, soient rédigés en langue anglaise seulement.


 


1.10                        Successors and Assigns


 


All covenants and
agreements in this Supplemental Indenture by the Company shall bind its
respective successors and assigns, whether expressed or not. All covenants and
agreements in this Supplemental Indenture by the Trustee shall bind its
successors, whether expressed or not.


 


3

















 


1.11                        Benefits of Supplemental Indenture


 


Nothing in this First
Supplemental Indenture or in the Series B Debentures, express or implied,
shall give to any Person, other than the parties hereto and their successors
hereunder, any paying agent, the holders of Series B Debentures, the
Senior Creditors (to the extent provided in Article 5 of the Trust
Indenture only), and (to the extent provided in Section 8.11 of the Trust
Indenture) the holders of Common Shares, any benefit or any legal or equitable
right, remedy or claim under this First Supplemental Indenture.


 


ARTICLE 2

TERMS OF SERIES B DEBENTURES


 


2.1                               Terms of Series B Debentures


 


(a)                                                          The Series B Debentures, being the second
series of Debentures authorized under the Trust Indenture, as supplemented by
this First Supplemental Indenture, for issue, is limited to an aggregate
principal amount of not more than $·  and shall be designated as “·% Series B Convertible Unsecured Subordinated Debentures due ·”.  For the avoidance of doubt,
the Series B Debentures include any and all such Debentures issued under
the Over-Allotment Option.


 


(b)                                                         The Series B Debentures shall be dated as of
the date hereof and shall mature on the Maturity Date.  The Series B Debentures shall bear
interest from the date of issue at the rate of ·% per annum, payable semi-annually in arrears on the · day of · and · in each year (each, an “Interest
Payment Date”) computed on the basis of a 360-day year composed of
twelve 30-day months.  The first such
payment will fall due on ·, · and the last such payment (representing interest payable from and
including the last Interest Payment Date to, but excluding, the Maturity Date
or the earlier date of redemption or conversion of the Series B
Debentures) will fall due on the Maturity Date or the earlier date of
redemption or conversion, payable after as well as before maturity and after as
well as before default, with interest on amounts in default at the same rate,
compounded semi-annually,  computed
on the basis of a 360-day year composed of twelve 30-day months.  For certainty, the first interest payment
will include interest accrued and unpaid from and including ·, 2010 up to, but excluding, ·, · which will be equal to $· for each $1,000
principal amount of the Series B Debentures.


 


(c)                                                          The Series B Debentures will be redeemable at
the option of the Company in accordance with the terms of Article 4 of the
Trust Indenture, provided that the Series B Debentures will not be
redeemable on or prior to · (except in certain
limited circumstances following a Change of Control as defined in the Trust
Indenture).  After · and prior to ·, the Series B
Debentures may be redeemed by the Company, in whole at any time or in part from
time to time, on notice as provided for in Section 4.3 of the Trust
Indenture, provided that the Current Market Price is not less than 125% of the
Conversion Price at the time notice of redemption is given.  On or after · and prior to the Maturity Date, the Series B Debentures may be
redeemed by the Company, in whole or in part from time to time, on notice as
provided for in Section 4.3 of the Trust Indenture.  In such 


 


4

















 


circumstances,
the Series B Debentures will be redeemable at a price equal to their
principal amount plus accrued and unpaid interest.  The Redemption Notice for the Series B
Debentures shall be substantially in the form of Schedule “B”.  In connection with the redemption of the Series B
Debentures, the Company may, at its option and subject to the provisions of Section 4.6
of the Trust Indenture and subject to regulatory approval, elect to satisfy its
obligation to pay all or a portion of the aggregate Redemption Price of the Series B
Debentures to be redeemed by issuing and delivering to the holders of such Series B
Debentures, such number of Freely Tradeable Common Shares as is obtained by
dividing the principal amount of the Series B Debentures which are to be
redeemed by 95% of the Current Market Price on the Redemption Date. If the
Corporation elects to exercise such option, it shall so specify and provide
details in the Redemption Notice.


 


(d)                                                         The Series B Debentures will be subordinated
to the Senior Indebtedness in accordance with the provisions of Article 5
of the Trust Indenture.  In accordance
with Section 2.12 of the Trust Indenture, the Series B Debentures and
each other series of Debentures issued under the Trust Indenture or under
indentures supplemental to the Trust Indenture, will rank pari passu with each other (regardless of
their actual date or terms of issue) and, except as prescribed by law, with all
other present and future subordinated indebtedness and unsecured indebtedness
of the Company, other than Senior Indebtedness.


 


(e)                                                          Upon and subject to the provisions and conditions
of Article 6 of the Trust Indenture, the holder of each Series B
Debenture shall have the right, at such holder’s option, at any time prior to
the close of business on the earlier of: (i) the Maturity Date; and (ii) the
last Business Day immediately preceding the Redemption Date specified by the
Company for redemption of the Series B Debentures by notice to the holders
of Series B Debentures in accordance with Section 2.1(c) of this
Supplemental Indenture and Section 4.3 of the Trust Indenture (the earlier
of which will be the “Time of Expiry” for the purposes of Article 6 of the Trust
Indenture in respect of the Series B Debentures), to convert the whole or,
in the case of a Debenture of a denomination in excess of $1,000, any part
which is $1,000 or an integral multiple thereof, of the principal amount of
such Debenture into Common Shares at the Conversion Price in effect on the Date
of Conversion (as defined in Section 6.4(b) of the Trust
Indenture).  To the extent a redemption
is a redemption in part only of the Series B Debentures, such right to
convert, if not exercised prior to the applicable Time of Expiry, shall survive
as to any Series B Debentures not redeemed or converted and be applicable
to the next succeeding Time of Expiry.


 


The Conversion
Price in effect on the date hereof for each Common Share to be issued upon the
conversion of Series B Debentures shall be equal to $· per Common Share being a conversion ratio of approximately · Common Shares for each $1,000 principal amount of Series B
Debentures so converted.  No adjustment
to the Conversion Price will be made for dividends or distributions payable on
Common Shares issuable upon conversion or for interest accrued or accruing on Series B
Debentures surrendered for conversion. 
Holders converting their Series B Debentures will receive interest
which has accrued but not been 


 


5

















 


paid from the date
of the most recent Interest Payment Date on which interest was paid in full in
accordance with this Supplemental Indenture to, but not including, the Date of
Conversion.  The Conversion Price
applicable to, and the Common Shares, securities or other property receivable
on the conversion of, the Series B Debentures is subject to adjustment
pursuant to the provisions of Section 6.5 of the Trust Indenture.


 


(f)                                                            The Series B Debentures shall be issued in
denominations of $1,000 and integral multiples of $1,000 and the Debenture
Trustee is hereby appointed as registrar and transfer agent for the Series B
Debentures.  Each Series B Debenture
and the certificate of the Debenture Trustee endorsed thereon shall be issued
in substantially the form set out in Schedule “A”,
with such insertions, omissions, substitutions or other variations as shall be
required or permitted by the Trust Indenture and this Supplemental Indenture,
and may have imprinted or otherwise reproduced thereon such legend or legends
or endorsements, not inconsistent with the provisions of the Trust Indenture
and this Supplemental Indenture, as may be required to comply with any law or
with any rules or regulations pursuant thereto or with any rules or
regulations of any securities exchange or securities regulatory authority or to
conform with general usage, all as may be determined by the Directors or an
Authorized Officer executing such Series B Debenture in accordance with Section 2.7
of the Trust Indenture, as conclusively evidenced by his or her execution of a Series B
Debenture.  Each Series B Debenture
shall additionally bear such distinguishing letters and numbers as the
Debenture Trustee shall approve. 
Notwithstanding the foregoing, a Series B Debenture may be in such
other form or forms as may, from time to time, be approved by a resolution of
the Directors or as specified in a Certificate. 
The Series B Debentures may be engraved, lithographed, printed,
mimeographed or typewritten or partly in one form and partly in another.


 


The Series B
Debentures shall be issued as one or more Global Debentures and the Global
Debentures will be registered in the name of the Depository which, as of the
date hereof, shall be CDS (or any nominee of the Depository).  No Beneficial Holder will receive definitive
certificates representing its interest in Debentures except as provided in Section 3.2
of the Trust Indenture.  A Global
Debenture may be exchanged for Debentures in registered form that are not
Global Debentures, or transferred to and registered in the name of a Person
other than the Depository for such Global Debentures or a nominee thereof as
provided in Section 3.2 of the Trust Indenture.


 


(g)                                                         Upon and subject to the provisions and conditions
of Article 10 of the Trust Indenture, and provided no Event of Default has
occurred and is continuing, the Company may elect, from time to time, to raise
funds to satisfy all or part of an Interest Obligation on the Series B
Debentures on any Interest Payment Date (including, for greater certainty, following
conversion or upon maturity or redemption) by delivering Common Shares to an
agent, including the Debenture Trustee, for sale through the facilities of a
registered broker/dealer.


 


6

















 


(h)                                                         Subject to Applicable Securities Legislation and
any required regulatory approval, upon the occurrence of a Change of Control
and subject to the provisions and conditions of this Section 2.1(h) and
Article 5 of the Trust Indenture, Debentureholders have a right to require
the Company to purchase all of their Series B Debentures.  The terms and conditions of such right are
set forth below.


 


(i)                                     Upon
the occurrence of a Change of Control, each holder of Series B Debentures
shall have the right (the “Put Right”) to require the Company to
purchase, on the date (the “Put Date”) which is 30 days
following the date upon which the Debenture Trustee delivers a Change of
Control Notice (as defined below) to the holders of Series B Debentures,
all or any part of such holder’s Series B Debentures at a price equal to
100% of the principal amount thereof (the “Put Price”) plus accrued and
unpaid interest, if any, on such Series B Debenture up to, but excluding,
the Put Date (collectively, the “Total Put Price”).


 


(ii)                                  The
Company will, as soon as practicable, and in any event no later than two
Business Days after the occurrence of a Change of Control, give written notice
to the Debenture Trustee of the Change of Control.  The Debenture Trustee will, as soon as
practicable thereafter, and in any event no later than four Business Days after
receiving notice from the Company of the Change of Control, provide written
notice to the holders of Series B Debentures of the Change of Control (a “Change of
Control Notice”).  The
Change of Control Notice shall include a description of the Change of Control,
details of the Debentureholders’ Put Right under the terms of the Trust
Indenture and the Supplemental Indenture (including identifying the Put Date),
a statement that each holder will be entitled to withdraw his election to
require the Company to purchase if the Debenture Trustee receives, no later
than the close of business on the third Business Day immediately preceding the
Put Date, a facsimile transmission or letter setting forth the name of such
holder, the principal amount of the Series B Debentures tendered for
purchase and a statement that such holder is withdrawing his election to have
the Series B Debentures purchased and a description of the rights of the
Company to redeem untendered Series B Debentures in accordance with
Section 2.1(h)(iv) hereof.


 


(iii)                               To
exercise the Put Right the Debentureholder must deliver to the Debenture
Trustee, not less than five Business Days prior to the Put Date, written notice
of the holder’s exercise of such right in the form attached as Schedule “E”.


 


(iv)                              If
90% or more in aggregate principal amount of Series B Debentures
outstanding on the date the Company provides notice of a Change of Control to
the Debenture Trustee have been tendered for purchase pursuant to the Put Right
on the Put Date, the Company shall have the right, upon written notice provided
to the Debenture Trustee within 10 days following the Put Date, to redeem all
the remaining outstanding Series B Debentures effective as of the Put Date
at the Total Put Price (the “90% Redemption Right”).


 


7

















 


(v)                                 Upon
receipt of notice that the Company shall exercise the 90% Redemption Right and
acquire the remaining Series B Debentures, the Debenture Trustee shall as
soon as reasonably practicable provide written notice to all Debentureholders
that did not previously exercise the Put Right that:


 


(A)                              the Company has exercised the
90% Redemption Right and will purchase all outstanding Series B Debentures
effective as of the Put Date at the Total Put Price, including a calculation of
such holder’s Total Put Price;


 


(B)                                each holder must transfer
their Series B Debentures to the Debenture Trustee on the same terms as
those holders that exercised the Put Right and must send their respective Series B
Debentures, duly endorsed for transfer, to the Debenture Trustee within 10 days
after the sending of such notice and the Depository shall make notations on the
Global Debenture of the principal amount thereof so transferred; and


 


(C)                                the rights of such holder
under the terms of the Series B Debentures, the Trust Indenture and this
Supplemental Indenture shall cease to be effective as of the Put Date provided
the Company has paid the Total Put Price to, or to the order of, the Debenture
Trustee and thereafter the Series B Debentures shall not be considered to
be outstanding and the holder shall not have any right except to receive such
holder’s Total Put Price upon surrender and delivery of such holder’s Series B
Debentures in accordance with the Trust Indenture and this Supplemental
Indenture.


 


(vi)                              The
Company shall, on or before 11:00 a.m. (Toronto time) on the Business Day
immediately prior to the Put Date, deposit with the Debenture Trustee or any
paying agent to the order of the Debenture Trustee, such sums of money as may
be sufficient to pay the Total Put Price of the Series B Debentures to be
purchased or redeemed by the Company on the Put Date, provided the Company may
elect to satisfy this requirement by providing the Debenture Trustee with a
certified cheque or wire transfer for such amounts required under this
Section 2.1(h)(vi).  The Company
shall also deposit with the Debenture Trustee a sum of money sufficient to pay
any charges or expenses that may be incurred by the Debenture Trustee in
connection with such purchase and/or redemption, as the case may be.  Every such deposit shall be irrevocable.  From the sums so deposited, the Debenture
Trustee shall pay or cause to be paid to the holders of such Series B Debentures,
the Total Put Price to which they are entitled (less any tax required by law to
be deducted in respect of accrued and unpaid interest) on the Company’s
purchase or redemption.


 


(vii)                           In
the event that one or more of such Series B Debentures being purchased in
accordance with this Section 2.1(h) becomes subject to purchase in
part only, upon surrender of such Series B Debentures for payment of the
Total 


 


8

















 


Put Price, the Depository
shall make notations on the Global Debenture of the principal amount thereof so
purchased.


 


(viii)                        Series B
Debentures for which holders have exercised the Put Right and Series B
Debentures which the Company has elected to redeem in accordance with the 90%
Redemption Right shall become due and payable at the Total Put Price on the Put
Date, in the same manner and with the same effect as if it were the date of
maturity specified in such Series B Debentures, anything therein or herein
to the contrary notwithstanding, and from and after such Put Date, if the money
necessary to purchase or redeem the Series B Debentures shall have been
deposited as provided in this Section 2.1(h) and affidavits or other
proofs satisfactory to the Debenture Trustee as to the publication and/or mailing
of such notices shall have been lodged with it, interest on the Series B
Debentures shall cease.  If any question
shall arise as to whether any notice has been given as above provided and such
deposit made, such question shall be decided by the Debenture Trustee whose
decision shall be final and binding upon all parties in interest.


 


(ix)                                In
case the holder of any Series B Debenture to be purchased or redeemed in
accordance with this Section 2.1(h) shall fail on or before the Put
Date to surrender such holder’s Series B Debenture or shall not within
such time accept payment of the money payable; or give such receipt therefor,
if any, as the Debenture Trustee may require, such monies may be set aside in
trust, either in the deposit department of the Debenture Trustee or in a
chartered bank, and such setting aside shall for all purposes be deemed a
payment to the Debentureholder of the sum so set aside and, to that extent, the
Series B Debenture shall thereafter not be considered as outstanding
hereunder and the Debentureholder shall have no other right except to receive
payment of the monies so paid and deposited, upon surrender and delivery up of
such holder’s Series B Debenture, of the Total Put Price.  In the event that any money required to be
deposited hereunder with the Debenture Trustee or any depository or paying
agent on account of the Total Put Price shall remain so deposited for a period
of six years from the Put Date, then such monies shall at the end of such
period be paid over or delivered over by the Debenture Trustee or such
depository or paying agent to the Company and the Debenture Trustee shall not
be responsible to Debentureholders for any amounts owing to them.


 


(x)                                   Subject
to the provisions above related to Series B Debentures purchased in part,
all Series B Debentures redeemed and paid under this Section 2.1(h) shall
forthwith be delivered to the Debenture Trustee and cancelled and no Series B
Debentures shall be issued in substitution therefor.


 


(i)                                                             In addition to the requirements of Section 2.1(h) in
respect of a Change of Control, the following provisions shall apply in respect
of the occurrence of a Cash Change of Control:


 


9














 


(i)                  In the event of the
occurrence of a Cash Change of Control, then subject to regulatory approval,
during the period (the “Cash Change of
Control Conversion Period”) beginning 10 trading days before the
anticipated effective date of the Change of Control (the “Effective Date”) and ending on the date
that is 30 days after the Change of Control Notice and Change of Control
Purchase Offer are delivered or mailed to holders of Series B  Debentures in accordance with Section 2.1(h),
holders of Series B Debentures will be entitled to convert their Series B
Debentures, in whole or in part, and receive, in addition to the number of
Common Shares (or cash or other property or securities in substitution
therefor) that such holders are entitled to receive upon such conversion in
accordance with the provisions and conditions of Sections 2.1(e) and 2.1(i) of
this First Supplemental Indenture and Article 6 of the Trust Indenture, an
additional number of Common Shares (or cash or other property or securities in
substitution therefor) per $1,000 principal amount of Series B Debentures
converted as set forth below (the “Make Whole
Premium”).


 


(ii)               The number of
additional Common Shares (or cash or other property or securities in
substitution therefor) per $1,000 principal amount of Series B Debentures
constituting the Make Whole Premium (the “Make
Whole Premium Shares”) shall be determined by reference to the table
following subsection (iii) below, based on the actual Effective Date and
the price (the “Stock Price”) paid
per Common Share in the transaction constituting the Change of Control. If
holders of Common Shares receive only cash in the transaction constituting the
Change of Control, the Stock Price shall be the cash amount paid per Common
Share. Otherwise, the Stock Price shall be equal to the Current Market Price of
the Common Shares immediately preceding the actual Effective Date of such
transaction. Notwithstanding the foregoing, in no circumstances can the
effective Conversion Price (calculated by dividing $1,000 by the number of
Common Shares issuable upon conversion, including the maximum number of Make
Whole Premium Shares hereunder) be less than the maximum permitted discounted
price permitted by the TSX at the time of announcement of the 2010 Offering
(estimated by the Company to be $·),
prior to any adjustments that may be made to the Stock Price to correspond to
an adjustment to the Conversion Price under the Trust Indenture or this First
Supplemental Indenture.


 


(iii)            The following table
shows the number of Make Whole Premium Shares for each hypothetical Stock Price
and Effective Date set forth below, expressed as additional Common Shares per
$1,000 principal amount of Debentures. For the avoidance of doubt, the Company
shall not be obliged to pay the Make Whole Premium otherwise than by issuance
of Common Shares (or cash or other property or securities in substitution
therefor) upon conversion of the Series B Debentures in accordance with
the provisions and conditions of Section 2.1(e) of this First
Supplemental Indenture and Article 6 of the Trust Indenture. If the Stock
Price or 


 


10

















 


Effective Date are not set
forth on the table then: (i) if the actual Stock Price on the Effective
Date is between two Stock Prices on the table or the Effective Date is between
two Effective Dates on the table, the number of Make Whole Premium Shares will
be determined by a straight-line interpolation between the amounts set forth
for the two Stock Prices and the two Effective Dates on the table based on a
365-day year, as applicable, (ii) if the Stock Price on the Effective Date
exceeds $· per
Common Share, subject to adjustment as set forth herein, the number of Make
Whole Premium Shares to be issued will be zero, and (iii) if the Stock
Price on the Effective Date is less than $· per Common Share, subject to adjustment as
set forth herein, the number of Make Whole Premium Shares to be issued will be
zero.


 


11

















 


Make
Whole Premium Upon a Cash Change of Control

(Number of Additional Common Shares per $1,000 Series B Debenture)


 


	
  Effective

  	
   

  	
   

  	
   

  
	
  Date

  	
   

  	
  Stock Price

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  



 


	
  Effective

  	
   

  	
   

  	
   

  
	
  Date

  	
   

  	
  Stock Price

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  



 


(iv)           The Stock Prices set
forth in the first row of table above will be adjusted as of any date on which
the Conversion Price of the Series B Debentures is adjusted. The adjusted
Stock Prices will equal the Stock Prices applicable immediately preceding such
adjustment multiplied by a fraction, the numerator of which is the Conversion
Price immediately preceding the adjustment giving rise to the Stock Price
adjustment and the denominator of which is the Conversion Price as so adjusted.
The number of additional Make Whole Premium Shares set forth in the table above
will be adjusted in the same manner as the Conversion Price as set forth in Section 6.5
of the Trust Indenture, other than as a result of an adjustment of the
Conversion Price by adding the Make Whole Premium as described above.


 


(v)              Notwithstanding the
foregoing, if the Date of Conversion of any Series B Debentures occurs
during the period beginning on the 10th trading day prior to the Effective Date and
ending at the close of business on the actual Effective Date, the holders of
such Series B Debentures shall, on conversion of their Series B
Debentures, only be entitled to receive that number of Make Whole Premium
Shares (as may be adjusted pursuant to Section 6.5 of the Trust Indenture)
on the Business Day immediately following the actual Effective Date and, for
greater certainty, only if the Change of Control occurs.


 


12

















 


(vi)           The Make Whole Premium
Shares shall be deemed to have been issued to a holder of Series B
Debentures who exercises conversion rights on or prior to the Effective Date
upon conversion of Series B Debentures on the Business Day immediately
following the Effective Date. Section 6.5 of the Trust Indenture shall
apply to such conversion and, for greater certainty, the former holders of Series B
Debentures in respect of which the Make Whole Premium Shares are issuable shall
be entitled to receive and shall accept, in lieu of the Make Whole Premium
Shares, the number of shares or other securities or cash or other property of
the Company or of the Person or other entity resulting from the transaction
that constitutes the Cash Change of Control that such holders would have been
entitled to receive if such holders had been the registered holders of the
applicable number of Make Whole Premium Shares on the Effective Date.


 


(vii)        Except as otherwise
provided in Section 2.1(h), all other provisions of this First
Supplemental Indenture and the Trust Indenture applicable to a conversion of Series B
Debentures shall apply to a conversion of Series B Debentures during the
Cash Change of Control Conversion Period.


 


(j)                                                             The Debenture Trustee shall be provided with the
documents and instruments referred to in Sections 2.5(b), (c) and (d) of
the Trust Indenture with respect to the Series B Debentures prior to the
issuance of the Series B Debentures.


 


2.2                               Delivery


 


The Series B
Debentures shall be executed by the Company and delivered to the Debenture
Trustee accompanied by the documentation contemplated in Section 2.5 of
the Trust Indenture.  Series B
Debentures issued in connection with the Over Allotment Option shall require
only a Written Direction of the Company and an Officer’s Certificate.  The opinion of counsel delivered on the date
hereof will include an opinion in respect of the Series B Debentures to be
issued in connection with the Over Allotment Option.


 


2.3                               Legends and Certification


 


The Series B
Debentures shall contain the legend as set out in Schedule “A” and the
Debenture Trustee’s certificate of authentication shall be in the form annexed
to that Schedule “A”.


 


ARTICLE 3

CONFIRMATION OF TRUST INDENTURE


 


3.1                               Confirmation of Trust Indenture


 


The Trust Indenture, as
supplemented by this First Supplemental Indenture, shall be and continue in
full force and effect and is hereby confirmed.


 


13

















 


ARTICLE 4

ACCEPTANCE OF TRUST BY DEBENTURE TRUSTEE


 


4.1                               Acceptance of Trust


 


The Debenture Trustee
hereby accepts the trusts in this Supplemental Indenture and in the Trust
Indenture declared and provided for and agrees to perform the same upon the
terms and conditions herein set forth and to hold all rights, privileges and
benefits conferred hereby and by law in trust for the various persons who shall
from time to time be Debentureholders, subject to all the terms and conditions
herein set forth.


 


ARTICLE 5

EXECUTION AND FORMAL DATE


 


5.1                               Execution


 


This First Supplemental
Indenture may be simultaneously executed in several counterparts, each of which
when so executed shall be deemed to be an original and such counterparts
together shall constitute one and the same instrument.


 


5.2                               Formal Date


 


For the purpose of
convenience this First Supplemental Indenture may be referred to as bearing the
formal date of  September ·, 2010 irrespective of the
actual date of execution hereof.


 


[Remainder of page intentionally left blank.  Signature page follows.]


 


14

















 


IN WITNESS WHEREOF the parties hereto have
executed this First Supplemental Indenture by the hands of their proper
officers.


 


 


	
   

  	
   

  	
  ATLANTIC
  POWER CORPORATION

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
   

  	
  Name: 

  
	
   

  	
   

  	
   

  	
  Title:

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  COMPUTERSHARE
  TRUST COMPANY OF CANADA

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
   

  	
  Name:

  
	
   

  	
   

  	
   

  	
  Title:

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
   

  	
  Name:

  
	
   

  	
   

  	
   

  	
  Title:

  



 


15






 










 


SCHEDULE
“A”


 


TO
THE FIRST SUPPLEMENTAL INDENTURE 

TO THE TRUST INDENTURE DATED DECEMBER 17, 2009 AMONG


 


ATLANTIC
POWER CORPORATION


 


-
and -


 


COMPUTERSHARE
TRUST COMPANY OF CANADA


 


Form of Debenture


 

















 


SCHEDULE “A”


 


FORM OF
GLOBAL DEBENTURE


 


UNLESS THIS CERTIFICATE
IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF CDS CLEARING AND DEPOSITORY
SERVICES INC. (“CDS”) TO ATLANTIC POWER
CORPORATION (THE “ISSUER”) OR ITS
AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE
ISSUED IN RESPECT THEREOF IS REGISTERED IN THE NAME OF CDS & CO., OR
IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF CDS (AND
ANY PAYMENT IS MADE TO CDS & CO. OR TO SUCH OTHER ENTITY AS IS
REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF CDS), ANY TRANSFER, PLEDGE OR
OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL SINCE
THE REGISTERED HOLDER HEREOF, CDS & CO., HAS A PROPERTY INTEREST IN
THE SECURITIES REPRESENTED BY THIS CERTIFICATE HEREIN AND IT IS A VIOLATION OF
ITS RIGHTS FOR ANOTHER PERSON TO HOLD, TRANSFER OR DEAL WITH THIS CERTIFICATE.


 


Certificate
No. ·


 


	
  CUSIP No.·

  	
   

  	
  CDN$·

  
	
  ISIN No. ·

  	
   

  	
   

  



 


ATLANTIC
POWER CORPORATION


(A
corporation continued under and governed by the laws of the Province of British
Columbia)


 


·% SERIES B CONVERTIBLE
UNSECURED SUBORDINATED DEBENTURE


DUE · (“Series B
Debenture”)


 


ATLANTIC POWER
CORPORATION (the  “Company”)
for value received hereby acknowledges itself indebted and, subject to the
provisions of the trust indenture (the “Indenture”)
dated as of December 17, 2009 between the Company and Computershare Trust
Company of Canada (the “Debenture Trustee”)
as amended and supplemented by the first supplemental indenture dated as of September ·, 2010 between the Company and
the Debenture Trustee (the “Supplemental Indenture”),
promises to pay to the registered holder hereof on · (the “Maturity Date”) or on such earlier date as
the principal amount hereof may become due in accordance with the provisions of
the Indenture and the Supplemental Indenture the principal sum of · dollars in lawful money of
Canada (CDN$·) on presentation and surrender of this
Debenture at the principal offices of the Debenture Trustee in Toronto, Ontario
in accordance with the terms of the Indenture and the Supplemental Indenture
and, subject as hereinafter provided, to pay interest on the principal amount
hereof from the date hereof, or from the last Interest Payment Date to which
interest shall have been paid or made available for payment hereon, whichever
is later, at the rate of ·% per annum, in like money, in
arrears semi-annually (less any withholding tax required or permitted by law to
be deducted) on · and · in each year commencing on · and the last payment
(representing interest payable from the last Interest Payment Date to, but excluding,
the Maturity Date or the earlier date of redemption) to fall due on the
Maturity Date and, should the Company at any time make default in the payment
of any principal, premium or interest, to pay interest on the amount in default
at the same rate, in like 


 

















 


money and on the same
dates.  For certainty, the first interest
payment will include interest accrued from · to, but excluding, ·, which will be equal to CDN$· for each CDN$1,000 principal
amount of the Series B Debentures.


 


Reference is hereby
expressly made to the Indenture and the Supplemental Indenture for a
description of the terms and conditions upon which the Series B Debentures
are or are to be issued and held and the rights and remedies of the holders of
the Series B Debentures and of the Company and of the Debenture Trustee,
all to the same effect as if the provisions of the Indenture and the
Supplemental Indenture were herein set forth, and to all of which provisions
the holder of this Series B Debenture by acceptance hereof assents.  To the extent that the terms and conditions
stated in this Debenture conflict with the terms and conditions of the
Indenture and the Supplemental Indenture, the Indenture and the Supplemental
Indenture shall prevail.  All capitalized
terms used herein have the meaning ascribed thereto in the Indenture and the
Supplemental Indenture unless otherwise indicated.


 


Interest hereon shall
be payable by electronic transfer of funds to the registered holder hereof or
such other means provided in the Indenture and the Supplemental Indenture and,
subject to the provisions of the Indenture and the Supplemental Indenture, the
sending of such electronic transfer of funds shall, to the extent of the sum
represented thereby (plus the amount of any tax withheld), satisfy and
discharge all liability for interest on this Series B Debenture.


 


This Series B
Debenture is one of the Debentures of the Company issued or issuable in one or
more series under the provisions of the Indenture.  The Series B Debentures authorized for
issue are limited to an aggregate principal amount of · dollars  in
lawful money of Canada (CDN$·).  The Series B Debentures are issuable
only in denominations of CDN$1,000 and integral multiples thereof.  Upon compliance with the provisions of the
Indenture and the Supplemental Indenture, Debentures of any denomination may be
exchanged for an equal aggregate principal amount of Debentures in any other
authorized denomination or denominations.


 


Any part, being
CDN$1,000 or an integral multiple thereof, of the principal of this Series B
Debenture, provided that the principal amount of this Series B Debenture
is in a denomination in excess of CDN$1,000, is convertible, at the option of
the holder hereof, upon surrender of this Series B Debenture at the
principal offices of the Debenture Trustee in the City of Toronto, Ontario, at
any time prior to the close of business on the Maturity Date or, if this Series B  Debenture is called for redemption on or
prior to such date, then up to but not after the close of business on the last
Business Day immediately preceding the date specified for redemption of this Series B
Debenture, into Common Shares (without adjustment for interest accrued hereon
or for dividends, distributions or interest payments on the Common Shares issuable
upon conversion)  at a conversion
price of CDN$· per Common Share (the “Conversion
Price”), being a conversion ratio of approximately · for each CDN$1,000 principal
amount of Debentures so converted, all subject to the terms and conditions and
in the manner set forth in the Indenture and the Supplemental Indenture.  The Indenture and the Supplemental Indenture
make provision for the adjustment of the Conversion Price in the events therein
specified, including the delivery of additional Common Shares (or cash or other
property or securities in substitution therefor) for a limited time following a
change of control.  No fractional Common
Shares will be issued on any conversion but in lieu thereof, the Company will
satisfy such fractional interest by a cash payment equal to the market price of
such fractional interest determined in accordance with the Indenture.  No adjustment to the Conversion Price will be
made for dividends or distributions payable on Common Shares issuable upon
conversion or for interest accrued or accruing on Series B Debentures
surrendered for conversion.  Holders
converting their Series B Debentures will receive interest which has
accrued and is unpaid in respect thereof from the 


 


2

















 


most recent Interest
Payment Date to which interest has been paid to, but not including, the Date of
Conversion.


 


This Series B
Debenture may be redeemed at the option of the Company on the terms and
conditions set out in the Indenture and the Supplemental Indenture at the
Redemption Price therein and herein set out provided that this Series B
Debenture is not redeemable prior to or on ·.  After · and prior to ·, this Series B Debenture
is redeemable at the option of the Company provided that the Current Market
Price is at least 125% of Conversion Price. 
On or after · and prior to the Maturity Date, the Series B
Debentures may be redeemed at any time by the Company.  In such circumstances, the Series B
Debentures will be redeemable at a price equal to their principal amount plus
accrued and unpaid interest.  In
connection with the redemption of the Series B Debentures, the Company
may, at its option and subject to regulatory approval, elect to satisfy its
obligation to pay all or a portion of the aggregate principal amount of
Debentures due upon redemption of the Series B Debentures by issuing and
delivering to the holders of such Series B Debentures, such number of
Freely Tradeable Common Shares as is obtained by dividing the principal amount
of the Series B Debentures which are to be redeemed by 95% of the Current
Market Price on the Redemption Date. If the Company elects to exercise such
option, it shall so specify and provide details in the Redemption Notice.


 


Upon the occurrence of
a Change of Control, each holder of Series B Debentures may subject to the
terms and provisions of Section 2.1(h) of the Supplemental Indenture
and Article 5 of the Indenture require the Company to purchase the whole
or any part of such holder’s Series B Debentures at a price equal to 100%
of the principal amount of such Series B Debentures plus accrued and
unpaid interest up to, but excluding, the date the Series B Debentures are
so repurchased (the “Put Right”).  The Company shall satisfy such purchase price
by payment in cash.  If 90% or more of
the principal amount of all Series B Debentures outstanding on the date
the Company provides notice of a Change of Control to the Debenture Trustee
have been tendered for purchase pursuant to the Put Right, the Company has the
right to redeem all the remaining outstanding Series B Debentures on the
same date and at the same price.


 


If an Offer for
outstanding Debentures of a series (other than Debentures held by or on behalf
of the Offeror, Associates or Affiliates of the Offeror or anyone acting
jointly or in concert with the Offeror) is made and 90% or more of the
outstanding principal amount of the Debentures is taken up and paid for by the
Offeror, the Offeror wil1 be entitled to acquire the Debentures of those
holders who did not accept the offer on the same terms as the Offeror acquired
the first 90% of the principal amount of the Debentures.


 


The Company may, on
notice as provided in the Indenture and the Supplemental Indenture, at its
option and subject to any applicable regulatory approval, elect to satisfy the
obligation to repay all or any portion of the principal amount of this Series B
Debenture due on the Maturity Date by the issue of that number of Freely
Tradeable Common Shares obtained by dividing the principal amount of the
outstanding Series B Debentures which have matured by 95% of the Current
Market Price on the Maturity Date.


 


The indebtedness
evidenced by this Series B Debenture, and by all other Series B
Debentures now or hereafter certified and delivered under the Indenture, is a
direct unsecured obligation of the Company, and is subordinated in right of
payment, to the extent and in the manner provided in the Indenture and the
Supplemental Indenture, to the prior payment in full of all Senior
Indebtedness, whether outstanding at the date of the Supplemental Indenture or
thereafter created, incurred, assumed or guaranteed.


 


3

















 


The principal hereof
may become or be declared due and payable before the stated maturity in the
events, in the manner, with the effect and at the times provided in the
Indenture and the Supplemental Indenture.


 


Any payment of money to
any holder of Debentures will be reduced by the amount of applicable
withholding taxes, if any.  The Indenture
and the Supplemental Indenture contain provisions making binding upon all
holders of Debentures outstanding thereunder (or in certain circumstances
specific series of Debentures) resolutions passed at meetings of such holders
held in accordance with such provisions and instruments signed by the holders
of a specified majority of Debentures outstanding (or specific series), which
resolutions or instruments may have the effect of amending the terms of this Series B
Debenture or the Indenture or the Supplemental Indenture.


 


This Series B
Debenture may only be transferred, upon compliance with the conditions
prescribed in the Indenture and the Supplemental Indenture, in one of the
registers to be kept at the principal offices of the Debenture Trustee in
Toronto and in such other place or places and/or by such other registrars (if
any) as the Company with the approval of the Debenture Trustee may
designate.  No transfer of this Series B
Debenture shall be valid unless made on the register by the registered holder
hereof and upon compliance with such reasonable requirements as the Debenture
Trustee and/or other registrar may prescribe and upon surrender of this Series B
Debenture for cancellation.  Thereupon a
new Series B Debenture or Series B Debentures in the same aggregate
principal amount shall be issued to the transferee in exchange hereof.


 


This Series B
Debenture shall not become obligatory for any purpose until it shall have been
certified by the Debenture Trustee under the Indenture and the Supplemental
Indenture.


 


The Indenture,
Supplemental Indenture and this Debenture shall be governed by, and construed
in accordance with, the laws of the Province of Ontario and the federal laws of
Canada applicable therein.


 


Capitalized words or
expressions used in this Series B Debenture shall, unless otherwise
defined herein, have the meaning ascribed thereto in the Indenture and the
Supplemental Indenture.  In the event that the terms and conditions stated in
this Debenture conflict, or are inconsistent, with the terms and conditions of
the Indenture and the Supplemental Indenture, the Indenture and Supplemental
Indenture, as applicable, shall prevail and take priority.


 


[The
remainder of this page has been intentionally left blank.]


 


4

















 


IN WITNESS WHEREOF
ATLANTIC POWER CORPORATION has caused this Debenture to be signed by its
authorized signatories as of the · day of September, 2010.


 


	
   

  	
  ATLANTIC
  POWER CORPORATION

  
	
   

  	
   

  
	
   

  	
  Per:

  	
   

  
	
   

  	
   

  	
  Name:

  
	
   

  	
   

  	
  Title:

  



 


5

















 


(FORM OF
DEBENTURE TRUSTEE’S CERTIFICATE)


 


This Series B
Debenture is one of the ·% Series B Convertible
Unsecured Subordinated Debentures due · referred to in the Indenture
and the Supplemental Indenture within mentioned.


 


	
   

  	
  COMPUTERSHARE TRUST
  COMPANY OF CANADA

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
  (Authorized Officer)

  	
   

  



 


(FORM OF
REGISTRATION PANEL)


 


(No
writing hereon except by Debenture Trustee or other registrar)


 


	
   

  	
  Signature of
  Debenture Trustee or

  
	
   

  	
  Registrar

  



 


CDS &
Co.

85 Richmond Street West

Toronto, Ontario

M5H 2C9


 


	
   

  	
  Date of Registration:

  	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  In Whose Name
  Registered: CDS & Co.

  



 

















 


FORM OF
ASSIGNMENT


 


FOR VALUE RECEIVED, the
undersigned hereby sells, assigns and transfers unto ·, whose address, if
applicable, is set forth below, this Series B Debenture (or $· principal amount hereof*) of
ATLANTIC POWER CORPORATION standing in the name(s) of the undersigned in
the register maintained by or on behalf of ATLANTIC POWER CORPORATION with
respect to such Series B Debenture and does hereby irrevocably authorize
and direct the Debenture Trustee to transfer such Series B Debenture in
such register, with full power of substitution in the premises.


 


	
  Dated:

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
  Address of
  Transferee:

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
  (Street Address,
  City, Province and Postal Code)

  	
   

  	
   

  	
   

  
							



 






(*) If less than the
full principal amount of the within Series B Debenture is to be
transferred, indicate in the space provided the principal amount (which must be
CDN$1,000 or an integral multiple thereof, unless you hold a Series B
Debenture in a non-integral multiple of CDN$1,000, in which case such Series B
Debenture is transferable only in its entirety) to be transferred.


 


 


	
   

  	
   

  
	
   

  	
  Signature of
  transferring registered holder

  



 

















 


EXHIBIT “1”


TO
CDS GLOBAL DEBENTURE


ATLANTIC
POWER CORPORATION


 


·% SERIES B CONVERTIBLE
UNSECURED SUBORDINATED DEBENTURES DUE ·


 


	
  Initial Principal Amount:

  	
  CDN$·

  	
   

  	
   

  	
  CUSIP
  No.·

  
	
   

  	
   

  	
   

  	
   

  	
  ISIN
  No. ·

  



 


	
  Signature of the
  Debenture Trustee:

  	
   

  	
   

  



 


ADJUSTMENTS


 


	
  Date

  	
   

  	
  Amount of

  Increase

  	
   

  	
  Amount of

  Decrease

  	
   

  	
  New Principal

  Amount

  	
   

  	
  Authorization

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  



 






 


 










 


SCHEDULE
“B”


 


TO
THE FIRST SUPPLEMENTAL INDENTURE 

TO THE TRUST INDENTURE DATED DECEMBER 17, 2009 AMONG


 


ATLANTIC
POWER CORPORATION


 


-
and -


 


COMPUTERSHARE
TRUST COMPANY OF CANADA


 


Form of
Redemption Notice


 

















 


SCHEDULE “B”


 


FORM OF REDEMPTION
NOTICE


 


To:                             Holders of ·% Series B Convertible Unsecured
Subordinated Debentures due · (the “Debentures”) of Atlantic Power Corporation
(the “Company”)


 


Note:                  All capitalized terms used herein have the
meaning ascribed thereto in the Indenture and the Supplemental Indenture
mentioned below, unless otherwise indicated.


 


Notice is hereby given
pursuant to Section 4.3 of the trust indenture (the “Indenture”) dated as of December 17,
2009 between the Company and Computershare Trust Company of Canada (the “Debenture Trustee”), as supplemented by the
first supplemental indenture to the Indenture (the “Supplemental
Indenture”) dated as of September ·, 2010 between the Company and
the Debenture Trustee, that the aggregate principal amount of CDN$· of the CDN$· of Debentures outstanding
will be redeemed as of ·, 20· (the “Redemption Date”), upon payment of a
redemption amount of CDN$· for each CDN$1,000 principal
amount of Debentures, being equal to the aggregate of (i) CDN$· (the “Redemption Price”), and (ii) accrued
and unpaid interest on such redeemed Debentures to but excluding the Redemption
Date, in each case less any withholding taxes required to be deducted
(collectively, the “Total Redemption Price”).


 


The Total Redemption
Price will be payable upon presentation and surrender of the Debentures called
for redemption at the following corporate trust office:


 


Computershare Trust
Company of Canada

100 University Ave., 9th Floor

Toronto, Ontario, M5J 2Y1

Attention:  ·


 


The interest upon the
principal amount of Debentures called for redemption shall cease to be payable
from and after the Redemption Date, unless payment of the Redemption Price
shall not be made on presentation for surrender of such Debentures at the
above-mentioned corporate trust office on or after the Redemption Date or prior
to the setting aside of the Redemption Price pursuant to the Indenture and the
Supplemental Indenture.


 


 


	
  DATED:

  	
   

  	
   

  
	
   

  	
   

  
	
  ATLANTIC
  POWER CORPORATION

  	
   

  
	
   

  	
   

  
	
  By:

  	
   

  	
   

  
	
   

  	
  Authorized Signatory

  	
   

  



 

















 


SCHEDULE
“C”


 


TO
THE FIRST SUPPLEMENTAL INDENTURE 

TO THE TRUST INDENTURE DATED DECEMBER 17, 2009 AMONG


 


ATLANTIC
POWER CORPORATION


 


-
and -


 


COMPUTERSHARE
TRUST COMPANY OF CANADA


 


Form of
Maturity Notice


 

















 


SCHEDULE “C”


 


FORM OF MATURITY
NOTICE


 


	
  TO:

  	
   

  	
  Holders of  ·% Series B Convertible
  Unsecured Subordinated Debentures due · (the “Debentures”)
  of Atlantic Power Corporation (the “Company”)

  
	
   

  	
   

  	
   

  
	
  AND TO:

  	
   

  	
  Computershare Trust
  Company of Canada, as Debenture Trustee

  
	
   

  	
   

  	
   

  
	
  NOTE:

  	
   

  	
  All capitalized terms
  used herein have the meaning ascribed thereto in the Indenture and the
  Supplemental Indenture mentioned below, unless otherwise indicated.

  



 


Notice is hereby given
pursuant to the trust indenture (the “Indenture”)
dated as of December 17, 2009 between the Company and Computershare Trust
Company of Canada, as debenture trustee (the “Debenture
Trustee”) as supplemented by the first supplemental indenture to the
Indenture (the “Supplemental Indenture”) dated as
of September ·, 2010 between the Company and the Debenture
Trustee, that the Debentures are due and payable as of · (the “Maturity
Date”) and the Company hereby advises the holders of Debentures that
it will deliver to holders of Debentures a cash payment upon presentation and
surrender of the Debentures representing any principal amount and all accrued
and unpaid interest to the Maturity Date, to which the holder is entitled.


 


	
  DATED:

  	
   

  	
  ·

  



 


 


	
   

  	
   

  	
  ATLANTIC
  POWER CORPORATION

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  Per:

  	
   

  
	
   

  	
   

  	
   

  	
   

  



 

















 


SCHEDULE
“D”


 


 TO THE FIRST SUPPLEMENTAL INDENTURE 

TO THE TRUST INDENTURE  DATED DECEMBER 17, 2009
AMONG


 


ATLANTIC
POWER CORPORATION


 


-
and -


 


COMPUTERSHARE
TRUST COMPANY OF CANADA


 


Form of
Notice of Conversion


 

















 


SCHEDULE “D”


 


FORM OF NOTICE OF
CONVERSION


 


TO:                           ATLANTIC POWER CORPORATION


 


Note:                  All capitalized terms used herein have the
meaning ascribed thereto in the Indenture and the Supplemental Indenture
mentioned below, unless otherwise indicated.


 


The undersigned
registered holder of ·% Series B Convertible Unsecured
Subordinated Debentures due · (the “Debentures”)  in the principal amount of CDN$· irrevocably elects to convert
such Debentures (or CDN$· principal amount thereof*) in
accordance with the terms of the trust indenture (the “Indenture”)
dated as of December 17, 2009 between Atlantic Power Corporation (the “Company”) and Computershare Trust Company of Canada, as
debenture trustee (the “Debenture Trustee”)
as supplemented by the first supplemental indenture to the Indenture (the “Supplemental Indenture”) dated as of September ·, 2010 between the Company and
the Debenture Trustee and tenders herewith the Debentures, and, if applicable,
directs that the Common Shares of the Company (or cash or other property or
securities in substitution therefor, if applicable) issuable upon a conversion
(net of applicable withholding taxes, if any) be issued and delivered to the
person indicated below.  (If Common
Shares are to be issued in the name of a person other than the holder, all
requisite transfer taxes must be tendered by the undersigned.)


 


	
  Dated:

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  (Signature of
  Registered Holder)

  



 






(*) If less than the
full principal amount of the Debentures, indicate in the space provided the
principal amount (which must be CDN$1,000 or integral multiples thereof).


 


(Print name in which
Common Shares are to be issued, delivered and registered)


 


	
  Name:

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  (Address)

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  (City, Province and
  Postal Code)

  	
   

  
	
   

  	
   

  	
   

  
	
  Name of guarantor:

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  Authorized signature:

  	
   

  	
   

  



 

















 


SCHEDULE
“E”


 


TO
THE FIRST SUPPLEMENTAL INDENTURE 

TO THE TRUST INDENTURE DATED DECEMBER 17, 2009 AMONG


 


ATLANTIC
POWER CORPORATION


 


-
and -


 


COMPUTERSHARE
TRUST COMPANY OF CANADA


 


Form of
Notice of Put Exercise


 

















 


SCHEDULE “E”


 


FORM OF NOTICE OF PUT
EXERCISE


 


(Change
of Control)


 


PUT EXERCISE


 


TO:                           ATLANTIC POWER CORPORATION
(the “Company”)


 


Note:                  All capitalized terms used
herein have the meaning ascribed thereto in the Indenture and the Supplemental
Indenture mentioned below, unless otherwise indicated.


 


The undersigned
registered holder of ·% Series B Convertible Unsecured
Subordinated Debentures due · (the “Debentures”)  in the principal amount of CDN$· irrevocably elects to put
such Debentures (or CDN$· principal amount thereof*) to
the Company to be purchased by the Company on · (the “Put Date”) in accordance with the terms of
the trust indenture (the “Indenture”)
dated as of December 17, 2009 between the Company and Computershare Trust
Company of Canada (the “Debenture Trustee”),
as supplemented by the first supplemental indenture to the Indenture (the “Supplemental Indenture”) dated as of September ·, 2010 between the Company and
the Debenture Trustee at a price of CDN$· for each CDN$1,000 principal
amount of Debentures plus all accrued and unpaid interest thereon (net of
applicable withholding tax, if any) to, but excluding, the Put Date
(collectively, the “Total Put Price”)
and tenders herewith the Debentures.


 


 


	
  Date:

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  (Signature of
  Registered Holder)

  



 






*                                         If less than the full
principal amount of the Debentures, indicate in the space provided the
principal amount (which must be CDN$1,000 or integral multiples thereof).


 


The total Put Price
(after deduction of applicable taxes) will be payable upon presentation and
surrender of the Debentures with this form on or after the Put Date at the
following corporate trust office:


 


Computershare Trust
Company of Canada

100 University Ave., 9th Floor

Toronto, Ontario M5J 2Y1


 


The interest upon the
principal amount of Debentures put to the Company shall cease to be payable
from and after the Put Date unless payment of the Total Put Price shall not be
made on presentation for surrender of such Debentures at the above mentioned
corporate trust office on or after the Put Date or prior to the setting aside
of the Total Put Price pursuant to the Indenture and the Supplemental
Indenture.