Exhibit 10.6


 


PRIVATE PLACEMENT SHARES PURCHASE AGREEMENT


 


THIS PRIVATE PLACEMENT
SHARES PURCHASE AGREEMENT, dated as of   , 2021 (as it may from time to time be amended, this “Agreement”),
is entered into by and between TortoiseEcofin Acquisition Corp. III, a Cayman Islands exempted company (the “Company”),
and TortoiseEcofin Borrower LLC, a Delaware limited liability company (the “Purchaser”).


 


WHEREAS, the Company
intends to consummate an initial public offering (the “Public Offering”) of the Company’s Class
A ordinary shares, par value $0.0001 per share (each, a “Share”), as set forth in the Company’s
registration statement on Form S-1, filed with the U.S. Securities and Exchange Commission (the “SEC”),
File Number 333-253586 (the “Registration Statement”), under the Securities Act of 1933, as amended
(the “Securities Act”).


 


WHEREAS, the Purchaser
has agreed to purchase an aggregate of 950,000 Shares (or up to 1,040,000 Shares if the over-allotment option in connection with
the Public Offering is exercised in full) (the “Private Placement Shares”).


 


NOW THEREFORE, in consideration
of the mutual promises contained in this Agreement and other good and valuable consideration, the receipt and sufficiency of which
are hereby acknowledged, the parties to this Agreement hereby, intending legally to be bound, agree as follows:


 


AGREEMENT


 


Section 1. Authorization,
Purchase and Sale; Terms of the Private Placement Shares.


 


A. Authorization
of the Private Placement Shares. The Company has duly authorized the issuance and sale of the Private Placement Shares to the
Purchaser.


 


B. Purchase
and Sale of the Private Placement Shares.


 


(i) On
the date that is one business day prior to the date of the consummation of the Public Offering or on such earlier time and date
as may be mutually agreed by the Purchaser and the Company (the “Initial Closing Date”), the Company
shall issue and sell to the Purchaser, and the Purchaser shall purchase from the Company, 950,000 Private Placement Shares at a
price of $10.00 per Private Placement Share for an aggregate purchase price of $9,500,000 (the “Purchase Price”).
The Purchaser shall pay the Purchase Price by wire transfer of immediately available funds in accordance with the Company’s
wiring instructions. On the Initial Closing Date, upon the payment by the Purchaser of the Purchase Price, the Company, at its
option, shall deliver a certificate evidencing the Private Placement Shares purchased by the Purchaser on such date duly registered
in the Purchaser’s name to the Purchaser or effect such delivery in book-entry form.


 






     


     


    

 


(ii) On
the date that is one business day prior to the date of the consummation of the closing of the over-allotment option in connection
with the Public Offering or on such earlier time and date as may be mutually agreed by the Purchaser and the Company (each such
date, an “Over-allotment Closing Date,” and each Over-allotment Closing Date (if any) and the Initial
Closing Date being sometimes referred to herein as a “Closing Date”), the Company shall issue and sell
to the Purchaser, and the Purchaser shall purchase from the Company, up to 1,040,000 Private Placement Shares at a price of $10.00
per Private Placement Share for an aggregate purchase price of up to $10,400,000 (if the over-allotment option in connection with
the Public Offering is exercised in full) (the “Over-allotment Purchase Price”). The Purchaser shall
pay the Over-allotment Purchase Price by wire transfer of immediately available funds to the Company in accordance with the Company’s
wiring instructions. On the Over-allotment Closing Date, upon the payment by the Purchaser of the Over-allotment Purchase Price,
the Company shall, at its option, deliver a certificate evidencing the Private Placement Shares purchased on such date duly registered
in the Purchaser’s name to the Purchaser or effect such delivery in book-entry form.


 


C. Terms
of the Private Placement Shares.


 


(i) The Private Placement
Shares are substantially identical to the Shares to be offered in the Public Offering except that the Purchaser agrees that (1) the
Private Placement Shares will not, except in limited circumstances, be transferable, assignable or salable until 30 days after the completion
of the Company’s initial business combination (the “Business Combination”) so long as they are held by
the Purchaser or its permitted transferees, and (2) the Private Placement Shares are being purchased pursuant to an exemption from
the registration requirements of the Securities Act and will become freely tradable only after the expiration of the lockup described
above in clause (1) and they are registered pursuant to the Registration Rights Agreement (as defined below), or an exemption from
registration is available and the restrictions described above in clause (1) have expired.


 


(ii) At
the time of the closing of the Public Offering, the Company and the Purchaser shall enter into a registration rights agreement
(the “Registration Rights Agreement”) pursuant to which the Company will grant certain registration rights
to the Purchaser relating to the Private Placement Shares.


 


Section 2. Representations
and Warranties of the Company. As a material inducement to the Purchaser to enter into this Agreement and purchase the Private
Placement Shares, the Company hereby represents and warrants to the Purchaser (which representations and warranties shall survive
each Closing Date) that:


 


A. Incorporation
and Corporate Power. The Company is an exempted company duly incorporated, validly existing and in good standing under the
laws of the Cayman Islands and is qualified to do business in every jurisdiction in which the failure to so qualify would reasonably
be expected to have a material adverse effect on the financial condition, operating results or assets of the Company. The Company
possesses all requisite corporate power and authority necessary to carry out the transactions contemplated by this Agreement.


 






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B. Authorization;
No Breach.


 


(i) The
execution, delivery and performance of this Agreement and the Private Placement Shares have been duly authorized by the Company
as of the Closing Date. This Agreement constitutes the valid and binding obligation of the Company, enforceable in accordance with
its terms, subject to bankruptcy, insolvency, fraudulent conveyance, reorganization, moratorium and other laws of general applicability
relating to or affecting creditors’ rights and to general equitable principles (whether considered in a proceeding in equity
or law). Upon issuance in accordance with, and payment pursuant to, the terms of this Agreement, the Private Placement Shares will
constitute valid and binding obligations of the Company, enforceable in accordance with their terms as of the Closing Date, subject
to bankruptcy, insolvency, fraudulent conveyance, reorganization, moratorium and other laws of general applicability relating to
or affecting creditors’ rights and to general equitable principles (whether considered in a proceeding in equity or law).


 


(ii) The
execution and delivery by the Company of this Agreement and the Private Placement Shares, the issuance and sale of the Private
Placement Shares and the fulfillment of and compliance with the respective terms hereof and thereof by the Company, do not and
will not as of the Closing Date (1) conflict with or result in a breach of the terms, conditions or provisions of, (2) constitute
a default under, (3) result in the creation of any lien, security interest, charge or encumbrance upon the Company’s
share capital or assets under, (4) result in a violation of, or (5) require any authorization, consent, approval, exemption
or other action by or notice or declaration to, or filing with, any court or administrative or governmental body or agency pursuant
to the amended and restated memorandum and articles of association of the Company (in effect on the date hereof or as may be amended
prior to completion of the contemplated Public Offering) or any material law, statute, rule or regulation to which the Company
is subject, or any agreement, order, judgment or decree to which the Company is subject, except for any filings required after
the date hereof under federal or state securities laws.


 


C. Title
to Securities. Upon issuance in accordance with, and payment pursuant to, the terms hereof and upon registration in the Company’s
register of members, the Private Placement Shares will be duly and validly issued, fully paid and non-assessable. Upon issuance
in accordance with, and payment pursuant to, the terms hereof and upon registration in the Company’s register of members,
the Purchaser will have good title to the Private Placement Shares, free and clear of all liens, claims and encumbrances of any
kind, other than (i) transfer restrictions hereunder and under the other agreements contemplated hereby, (ii) transfer
restrictions under federal and state securities laws, and (iii) liens, claims or encumbrances imposed due to the actions of
the Purchaser.


 


D. Governmental
Consents. No permit, consent, approval or authorization of, or declaration to or filing with, any governmental authority is
required in connection with the execution, delivery and performance by the Company of this Agreement or the consummation by the
Company of any other transactions contemplated hereby.


 


E. Regulation
D Qualification. Neither the Company nor, to its actual knowledge, any of its affiliates, members, officers, directors or beneficial
shareholders of 20% or more of its outstanding securities, has experienced a disqualifying event as enumerated pursuant to Rule
506(d) of Regulation D under the Securities Act.


 






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Section 3. Representations
and Warranties of the Purchaser. As a material inducement to the Company to enter into this Agreement and issue and sell the
Private Placement Shares to the Purchaser, the Purchaser hereby represents and warrants to the Company (which representations and
warranties shall survive each Closing Date) that:


 


A. Organization
and Requisite Authority. The Purchaser possesses all requisite power and authority necessary to carry out the transactions
contemplated by this Agreement.


 


B. Authorization;
No Breach.


 


(i) This
Agreement constitutes a valid and binding obligation of the Purchaser, enforceable in accordance with its terms, subject to bankruptcy,
insolvency, fraudulent conveyance, reorganization, moratorium and other laws of general applicability relating to or affecting
creditors’ rights and to general equitable principles (whether considered in a proceeding in equity or law).


 


(ii) The
execution and delivery by the Purchaser of this Agreement and the fulfillment of and compliance with the terms hereof by the Purchaser
does not and shall not as of each Closing Date conflict with or result in a breach by the Purchaser of the terms, conditions or
provisions of any agreement, instrument, order, judgment or decree to which the Purchaser is subject.


 


C. Investment
Representations.


 


(i) The
Purchaser is acquiring the Private Placement Shares for its own account, for investment purposes only and not with a view towards,
or for resale in connection with, any public sale or distribution thereof.


 


(ii) The
Purchaser is an “accredited investor” as such term is defined in Rule 501(a)(3) of Regulation D under the Securities
Act.


 


(iii) The
Purchaser understands that the Private Placement Shares are being offered and will be sold to it in reliance on specific exemptions
from the registration requirements of the United States federal and state securities laws and that the Company is relying upon
the truth and accuracy of, and the Purchaser’s compliance with, the representations and warranties of the Purchaser set forth
herein in order to determine the availability of such exemptions and the eligibility of the Purchaser to acquire such Private Placement
Shares.


 


(iv) The
Purchaser did not decide to enter into this Agreement as a result of any general solicitation or general advertising within the
meaning of Rule 502(c) of Regulation D under the Securities Act.


 


(v) The
Purchaser has been furnished with all materials relating to the business, finances and operations of the Company and materials
relating to the offer and sale of the Private Placement Shares which have been requested by the Purchaser. The Purchaser has been
afforded the opportunity to ask questions of the executive officers and directors of the Company. The Purchaser understands that
its investment in the Private Placement Shares involves a high degree of risk and it has sought such accounting, legal and tax
advice as it has considered necessary to make an informed investment decision with respect to the acquisition of the Private Placement
Shares.


 






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(vi) The
Purchaser understands that no United States federal or state agency or any other government or governmental agency has passed on
or made any recommendation or endorsement of the Private Placement Shares or the fairness or suitability of the investment in the
Private Placement Shares by the Purchaser nor have such authorities passed upon or endorsed the merits of the offering of the Private
Placement Shares.


 


(vii) The
Purchaser understands that: (1) the Private Placement Shares have not been and are not being registered under the Securities
Act or any state securities laws, and may not be offered for sale, sold, assigned or transferred unless (a) subsequently registered
thereunder or (b) sold in reliance on an exemption therefrom; (2) except as specifically set forth in the Registration
Rights Agreement, neither the Company nor any other person is under any obligation to register the Private Placement Shares under
the Securities Act or any state securities laws or to comply with the terms and conditions of any exemption thereunder; and (3)
Rule 144 adopted pursuant to the Securities Act will not be available for resale transactions of the Private Placement Shares prior
to a business combination and may not be available for resale transactions of the Private Placement Shares after a business combination.


 


(viii) The
Purchaser has such knowledge and experience in financial and business matters, knows of the high degree of risk associated with
investments in the securities of companies in the development stage such as the Company, is capable of evaluating the merits and
risks of an investment in the Private Placement Shares and is able to bear the economic risk of an investment in the Private Placement
Shares in the amount contemplated hereunder for an indefinite period of time. The Purchaser has adequate means of providing for
its current financial needs and contingencies and will have no current or anticipated future needs for liquidity which would be
jeopardized by the investment in the Private Placement Shares. The Purchaser can afford a complete loss of its investment in the
Private Placement Shares.


 


(ix) If
the Company issues a certificate representing the Private Placement Shares, the Purchaser understands that the Private Placement
Shares shall bear the following legend and appropriate “stop transfer restrictions”:


 


“THE SECURITIES
REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE UNITED STATES SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE SECURITIES
LAWS, AND NEITHER THE SECURITIES NOR ANY INTEREST THEREIN MAY BE OFFERED, SOLD, TRANSFERRED, CHARGED, PLEDGED OR OTHERWISE DISPOSED
OF EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER SUCH ACT OR SUCH LAWS OR AN EXEMPTION FROM REGISTRATION UNDER SUCH
ACT AND SUCH LAWS WHICH, IN THE OPINION OF COUNSEL, IS AVAILABLE.


 


THE SECURITIES
REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO LOCKUP PROVISIONS AND MAY NOT BE OFFERED, SOLD, TRANSFERRED, CHARGED, PLEDGED OR
OTHERWISE DISPOSED OF DURING THE TERM OF THE LOCKUP.”


 






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Section 4. Conditions
of the Purchaser’s Obligations. The obligations of the Purchaser to purchase and pay for the Private Placement Shares
are subject to the fulfillment, on or before each Closing Date, of each of the following conditions:


 


A. Representations
and Warranties. The representations and warranties of the Company contained in Section 2 shall be true and correct at and as
of such Closing Date as though then made.


 


B. Performance.
The Company shall have performed and complied with all agreements, obligations and conditions contained in this Agreement that
are required to be performed or complied with by it on or before such Closing Date.


 


C. No
Injunction. No litigation, statute, rule, regulation, executive order, decree, ruling or injunction shall have been enacted,
entered, promulgated or endorsed by or in any court or governmental authority of competent jurisdiction or any self-regulatory
organization having authority over the matters contemplated hereby, which prohibits the consummation of any of the transactions
contemplated by this Agreement.


 


D. Registration
Rights Agreement. The Company shall have entered into the Registration Rights Agreement on the terms satisfactory to the Purchaser.


 


Section 5. Conditions
of the Company’s Obligations. The obligations of the Company to the Purchaser under this Agreement are subject to the
fulfillment, on or before each Closing Date, of each of the following conditions:


 


A. Representations
and Warranties. The representations and warranties of the Purchaser contained in Section 3 shall be true and correct at and
as of such Closing Date as though then made.


 


B. Performance.
The Purchaser shall have performed and complied with all agreements, obligations and conditions contained in this Agreement that
are required to be performed or complied with by the Purchaser on or before such Closing Date.


 


C. Corporate
Consents. The Company shall have obtained the consent of its Board of Directors authorizing the execution, delivery and performance
of this Agreement and the issuance and sale of the Private Placement Shares hereunder.


 


D. No
Injunction. No litigation, statute, rule, regulation, executive order, decree, ruling or injunction shall have been enacted,
entered, promulgated or endorsed by or in any court or governmental authority of competent jurisdiction or any self-regulatory
organization having authority over the matters contemplated hereby, which prohibits the consummation of any of the transactions
contemplated by this Agreement.


 






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Section 6. Termination.
This Agreement may be terminated at any time after [●], 2021 upon the election by either the Company or the Purchaser upon
written notice to the other party if the closing of the Public Offering does not occur prior to such date.


 


Section 7. Survival
of Representations and Warranties. All of the representations and warranties contained herein shall survive each Closing Date.


 


Section 8. Definitions.
Terms used but not otherwise defined in this Agreement shall have the meaning assigned to such terms in the Registration Statement.


 


Section 9. Miscellaneous.


 


A. Successors
and Assigns. Except as otherwise expressly provided herein, all covenants and agreements contained in this Agreement by or
on behalf of any of the parties hereto shall bind and inure to the benefit of the respective successors of the parties hereto whether
so expressed or not. Notwithstanding the foregoing or anything to the contrary herein, the parties may not assign this Agreement,
other than assignments by the Purchaser to affiliates thereof (including, without limitation, one or more of its members).


 


B. Severability.
Whenever possible, each provision of this Agreement shall be interpreted in such manner as to be effective and valid under applicable
law, but if any provision of this Agreement is held to be prohibited by or invalid under applicable law, such provision shall be
ineffective only to the extent of such prohibition or invalidity, without invalidating the remainder of this Agreement.


 


C. Counterparts.
This Agreement may be executed simultaneously in two or more counterparts, none of which need contain the signatures of more than
one party, but all such counterparts taken together shall constitute one and the same agreement. Signatures to this Agreement transmitted
via facsimile or e-mail shall be valid and effective to bind the party so signing.


 


D. Descriptive
Headings; Interpretation. The descriptive headings of this Agreement are inserted for convenience only and do not constitute
a substantive part of this Agreement. The use of the word “including” in this Agreement shall be by way of example
rather than by limitation.


 


E. Governing
Law. This Agreement shall be deemed to be a contract made under the laws of the State of New York and for all purposes shall
be construed in accordance with the internal laws of the State of New York, without giving effect to conflicts of law principles
that would result in the application of the laws of another jurisdiction.


 


F. Amendments.
This Agreement may not be amended, modified or waived as to any particular provision, except by a written instrument executed by
the parties hereto.


 


[Signature page follows]


 




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IN WITNESS WHEREOF,
the parties hereto have executed this Agreement to be effective as of the date first set forth above.


 


	   	COMPANY:
	 	 	 
	 	TORTOISEECOFIN ACQUISITION CORP. III
	 	 	 
	 	By:	                                      
	 	Name: 	Vincent T. Cubbage
	 	Title:	Chief Executive Officer
	 	 	 
	 	PURCHASER:
	 	 	 
	 	TORTOISEECOFIN BORROWER LLC
	 	 	 
	 	By:	 
	 	Name:	Michelle Johnston
	 	Title:	Chief Financial Officer



 


[Signature Page to Private Placement
Shares Purchase Agreement]