Exhibit 10.1


 


November 1, 2022


 


M3-Brigade Acquisition III Corp.

1700 Broadway, 19th Floor

New York, NY 10019


 


Re: Letter Agreement


 


Ladies and Gentlemen:


 


This letter (this “Letter Agreement”)
is being delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) entered into
by and between M3-Brigade Acquisition III Corp., a Delaware corporation (the “Company”), and Cantor Fitzgerald &
Co., as representative (the “Representative”) of the several underwriters (each, an “Underwriter”
and collectively, the “Underwriters”), relating to an underwritten initial public offering (the “Public Offering”),
of up to 46,000,000 of the Company’s units (including up to 6,000,000 units that may be purchased to cover over-allotments, if any)
(the “Units”), each comprised of one share of the Company’s Class A common stock, par value $0.0001 per share
(the “Class A Common Stock”), and one-third of one redeemable warrant. Each whole warrant (each, a “Warrant”)
entitles the holder thereof to purchase one share of Class A Common Stock at a price of $11.50 per share, subject to adjustment as described
in the Prospectus (as defined below). The Units were sold in the Public Offering pursuant to a registration statement on Form S-1 and
prospectus (the “Prospectus”) filed by the Company with the U.S. Securities and Exchange Commission (the “Commission”)
and the Units are listed on the New York Stock Exchange. Certain capitalized terms used herein are defined in paragraph 11 hereof.


 


For good and valuable consideration, the receipt
and sufficiency of which are hereby acknowledged, each of the undersigned individuals, each of whom is a member of the Company’s
board of directors and/or management team (each of the undersigned individuals, an “Insider” and collectively,
the “Insiders”), hereby agrees with the Company as follows:


 


1. Each
Insider agrees that if the Company seeks stockholder approval of a proposed Business Combination, then in connection with such proposed
Business Combination, it, he or she shall (i) vote any shares of Common Stock (as defined below) owned by it, him or her in favor of any
proposed Business Combination and (ii) not redeem any shares of Common Stock owned by it, him or her in connection with such stockholder
approval. If the Company seeks to consummate a proposed Business Combination by engaging in a tender offer, each Insider agrees that it,
he or she will not sell or tender any shares of Common Stock owned by it, him or her in connection therewith. The Company has agreed not
to enter into a definitive agreement with respect to an initial business combination without the written consent of M3-Brigade Sponsor
III LP (the “Sponsor”).


 


2. Each
Insider hereby agrees that in the event that the Company fails to consummate a Business Combination within 24 months from the closing
of the Public Offering, or such later period approved by the Company’s stockholders in accordance with the Company’s amended
and restated certificate of incorporation (as it may be amended from time to time, the “Charter”), each Insider
shall take all reasonable steps to cause the Company to (i) cease all operations except for the purpose of winding up, (ii) as promptly
as reasonably possible but not more than ten business days thereafter, redeem 100% of the shares of Class A Common Stock sold as part
of the Units in the Public Offering (the “Offering Shares”), at a per-share price, payable in cash, equal to
the aggregate amount then on deposit in the Trust Account (as defined below), including interest earned on the funds held in the Trust
Account (which interest shall be net of taxes payable and up to $100,000 of interest to pay dissolution expenses), divided by the number
of then outstanding Offering Shares, which redemption will completely extinguish all Public Stockholders’ rights as stockholders
(including the right to receive further liquidating distributions, if any), and (iii) as promptly as reasonably possible following such
redemption, subject to the approval of the Company’s remaining stockholders and the Company’s board of directors, liquidate
and dissolve, subject in each case to the Company’s obligations under Delaware law to provide for claims of creditors and other
requirements of applicable law. Each Insider agrees to not propose any amendment to the Charter to modify the substance or timing of the
Company’s obligation to redeem 100% of the Offering Shares if the Company does not complete a Business Combination within the required
time period set forth in the Charter or with respect to any other material provisions relating to stockholders’ rights or pre-initial
business combination activity, unless the Company provides its Public Stockholders with the opportunity to redeem their Offering Shares
upon approval of any such amendment at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust
Account, including interest earned on the funds held in the Trust Account (which interest shall be net of taxes payable and up to $100,000
of interest to pay dissolution expenses), divided by the number of then outstanding Offering Shares.


 






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Each Insider acknowledges that it, he or she has
no right, title, interest or claim of any kind in or to any monies held in the Trust Account or any other asset of the Company as a result
of any liquidation of the Company with respect to the Founder Shares held by it, him or her. Each Insider hereby further waives, with
respect to any shares of Common Stock held by it, him or her, if any, any redemption rights it, he or she may have in connection with
(A) the consummation of a Business Combination, including, without limitation, any such rights available in the context of a stockholder
vote to approve such Business Combination, or (B) a stockholder vote to approve an amendment to the Charter to modify the substance or
timing of the Company’s obligation to redeem 100% of the Offering Shares if the Company has not consummated a Business Combination
within the time period set forth in the Charter or with respect to any other material provisions relating to stockholders’ rights
or pre-initial business combination activity or in the context of a tender offer made by the Company to purchase Offering Shares (although
the Sponsor, the Insiders and their respective affiliates shall be entitled to redemption and liquidation rights with respect to any Offering
Shares it or they hold if the Company fails to consummate a Business Combination within the time period set forth in the Charter).


 


3. During
the period commencing on the effective date of the Underwriting Agreement and ending 180 days after such date, each Insider shall not,
other than as permitted in the Amended and Restated Operating Agreement of the Sponsor, as amended, supplemented or modified, from time
to time, without the prior written consent of the Representative, (i) sell, offer to sell, contract or agree to sell, hypothecate, pledge,
grant any option to purchase or otherwise dispose of or agree to dispose of, directly or indirectly, or establish or increase a put equivalent
position or liquidate or decrease a call equivalent position within the meaning of Section 16 of the Securities Exchange Act of 1934,
as amended (the “Exchange Act”), and the rules and regulations of the Commission promulgated thereunder, with
respect to, any Units, shares of Common Stock (including, but not limited to, Founder Shares), Warrants or any securities convertible
into, or exercisable, or exchangeable for, shares of Common Stock owned by it, him or her, (ii) enter into any swap or other arrangement
that transfers to another, in whole or in part, any of the economic consequences of ownership of any Units, shares of Common Stock (including,
but not limited to, Founder Shares), Warrants or any securities convertible into, or exercisable, or exchangeable for, shares of Common
Stock owned by it, him or her, whether any such transaction is to be settled by delivery of such securities, in cash or otherwise, or
(iii) publicly announce any intention to effect any transaction specified in clause (i) or (ii). For the avoidance of doubt, none of the
provisions of this Section 3 shall apply for any transactions entered into in connection with the consummation of an initial Business
Combination.


 


4. [Reserved].


 


5. [Reserved].


 


6. Each
Insider hereby agrees and acknowledges that: (i) the Underwriters and the Company would be irreparably injured in the event of a breach
by such Insider of its, his or her obligations under paragraphs 1, 2, 3, 4, 7, 7(b) and 9, as applicable, of this Letter Agreement (ii)
monetary damages may not be an adequate remedy for such breach and (iii) the non-breaching party shall be entitled to injunctive relief,
in addition to any other remedy that such party may have in law or in equity, in the event of such breach.


 


7. (a)
Each Insider agrees that it, he or she shall not Transfer any Founder Shares (or any shares of Class A Common Stock issuable upon conversion
thereof) until the earlier of (A) one year after the completion of the Company’s initial Business Combination and (B) subsequent
to the Business Combination, (x) if the closing price of the Class A Common Stock equals or exceeds $12.00 per share (as adjusted for
stock splits, stock dividends, reorganizations, recapitalizations and the like) for any 20 trading days within any 30-trading day period
commencing at least 150 days after the Company’s initial Business Combination or (y) the date on which the Company completes
a liquidation, merger, capital stock exchange, reorganization or other similar transaction that results in all of the Company’s
stockholders having the right to exchange their shares of Class A Common Stock for cash, securities or other property (the “Founder
Shares Lock-up Period”).


 






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(b) Each
Insider agrees that it, he or she shall not Transfer any Private Placement Warrants (or any share of Class A Common Stock issued or issuable
upon the exercise of the Private Placement Warrants), until 30 days after the completion of a Business Combination (the “Private
Placement Warrants Lock-up Period”, together with the Founder Shares Lock-up Period, the “Lock-up Periods”).


 


(c) Notwithstanding
the provisions set forth in paragraphs 7(a) and (b), Transfers of the Founder Shares, Private Placement Warrants and shares of Class A
Common Stock issued or issuable upon the exercise or conversion of the Private Placement Warrants or the Founder Shares that are held
by the Sponsor, any Insider or any of their permitted transferees (that have complied with this paragraph 7(c)), are permitted (i) to
the Company’s officers or directors, any affiliate or family member of any of the Company’s officers or directors, any affiliate
of the Sponsor or to any members of the Sponsor or any of their affiliates; (ii) in the case of an individual, by gift to a member of
such individual’s immediate family or to a trust, the beneficiary of which is a member of such individual’s immediate family,
an affiliate of such individual or to a charitable organization; (iii) in the case of an individual, by virtue of laws of descent and
distribution upon death of such individual; (iv) in the case of an individual, pursuant to a qualified domestic relations order; (v) by
private sales or transfers made in connection with any forward purchase agreement or any financing transaction or similar arrangement
or in connection with the consummation of an initial Business Combination at prices no greater than the price at which each type of security
was originally purchased; (vi) in the event of the Company’s liquidation prior to the completion of an initial Business Combination;
(vii) by virtue of the laws of the State of Delaware (viii) the Amended and Restated Operating Agreement of the Sponsor, as amended, supplemented
or modified, from time to time ; or (ix) in the event of the Company’s liquidation, merger, capital stock exchange or other similar
transaction which results in all of the Company’s stockholders having the right to exchange their shares of Class A Common Stock
for cash, securities or other property subsequent to the Company’s completion of an initial Business Combination; provided, however,
that in the case of clauses (i) through (ix), these permitted transferees must enter into a written agreement with the Company agreeing
to be bound by the transfer restrictions herein and the other restrictions contained in this Agreement (including provisions relating
to voting, the Trust Account and liquidating distributions).


 






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8. Each
Insider represents and warrants that it, he or she has never been suspended or expelled from membership in any securities or commodities
exchange or association or had a securities or commodities license or registration denied, suspended or revoked. Each Insider’s
biographical information furnished to the Company (including any such information included in the Prospectus) is true and accurate in
all respects and does not omit any material information with respect to the Insider’s background. Each Insider’s questionnaire
furnished to the Company is true and accurate in all respects. Each Insider represents and warrants that: it, he or she is not subject
to or a respondent in any legal action for, any injunction, cease-and-desist order or order or stipulation to desist or refrain from any
act or practice relating to the offering of securities in any jurisdiction; it, he or she has never been convicted of, or pleaded guilty
to, any crime (i) involving fraud, (ii) relating to any financial transaction or handling of funds of another person, or (iii) pertaining
to any dealings in any securities and it, he or she is not currently a defendant in any such criminal proceeding.


 


9. Except
as disclosed in the Prospectus, neither the Sponsor nor any officer, nor any affiliate of the Sponsor or any officer, nor any director
of the Company, shall receive from the Company any finder’s fee, reimbursement, consulting fee, non-cash payments, monies in respect
of any repayment of a loan or other compensation prior to, or in connection with any services rendered in order to effectuate, the consummation
of the Company’s initial Business Combination (regardless of the type of transaction that it is), other than the following, none
of which will be made from the proceeds held in the Trust Account prior to the completion of the initial Business Combination: repayment
of a loan and advances up to an aggregate of $300,000 made to the Company by the Sponsor to cover offering-related and organizational
expenses; cash compensation to an affiliate of the Sponsor, for any financial advisory, placement agency or other similar investment banking
services that such affiliate may provide to our company, in connection with our initial Business Combination upon the consummation of
our initial business combination, and reimbursement to such affiliate for any out-of-pocket expenses incurred by it in connection with
the performance of such services; reimbursement for any reasonable out-of-pocket expenses related to identifying, investigating, negotiating
and consummating an initial Business Combination, and repayment of non-interest bearing loans which may be made by the Sponsor or an affiliate
of the Sponsor or certain of the Company’s officers and directors to finance transaction costs in connection with an intended initial
Business Combination, provided, that, if the Company does not consummate an initial Business Combination, a portion of the working capital
held outside the Trust Account may be used by the Company to repay such loaned amounts so long as no proceeds from the Trust Account are
used for such repayment. Up to $1,500,000 of such loans may be convertible into warrants of the post-business combination entity at a
price of $1.50 per warrant at the option of the lender Such warrants would be identical to the Private Placement Warrants (as defined
below), including as to exercise price, exercisability and exercise period.


 






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10. Each
Insider has full right and power, without violating any agreement to which it is bound (including, without limitation, any non-competition
or non-solicitation agreement with any employer or former employer), to enter into this Letter Agreement and, as applicable, to serve
as an officer and/or director on the board of directors of the Company and hereby consents to being named in the Prospectus as an officer
and/or director of the Company.


 


11. As
used herein, (i) “Business Combination” shall mean a merger, capital stock exchange, asset acquisition, stock
purchase, reorganization or similar business combination, involving the Company and one or more businesses; (ii) “Common Stock”
shall mean the Class A common stock and Class B common stock, par value $0.0001 per share (“Class B Common Stock”);
(iii) “Founder Shares” shall mean the 11,500,000 shares of Class B common stock issued and outstanding (up to
1,500,000 Shares of which are subject to complete or partial forfeiture if the over-allotment option is not exercised by the Underwriters);
(iv) “Initial Stockholders” shall mean the Sponsor and any Insider that holds Founder Shares; (v) “Private
Placement Warrants” shall mean the 7,500,000 Warrants that the Sponsor has agreed to purchase for an aggregate purchase
price of $11,250,000, or $1.50 per Warrant, in a private placement that shall occur simultaneously with the consummation of the Public
Offering; (vi) “Public Stockholders” shall mean the holders of securities issued in the Public Offering;
(vii) “Trust Account” shall mean the trust fund into which a portion of the net proceeds of the Public Offering
and the sale of the Private Placement Warrants shall be deposited; (viii) “Transfer” shall mean the (a)
sale of, offer to sell, contract or agreement to sell, hypothecate, pledge, grant of any option to purchase or otherwise dispose of or
agreement to dispose of, directly or indirectly, or establishment or increase of a put equivalent position or liquidation with respect
to or decrease of a call equivalent position within the meaning of Section 16 of the Exchange Act, and the rules and regulations of the
Commission promulgated thereunder with respect to, any security, (b) entry into any swap or other arrangement that transfers to another,
in whole or in part, any of the economic consequences of ownership of any security, whether any such transaction is to be settled by delivery
of such securities, in cash or otherwise, or (c) public announcement of any intention to effect any transaction specified in clause (a)
or (b); and (ix) “Warrants” shall mean the Private Placement Warrants and public warrants.


 


12. The
Company will maintain an insurance policy or policies providing directors’ and officers’ liability insurance, and each Director
shall be covered by such policy or policies, in accordance with its or their terms, to the maximum extent of the coverage available for
any of the Company’s directors or officers.


 


13. This
Letter Agreement constitutes the entire agreement and understanding of the parties hereto in respect of the subject matter hereof and
supersedes all prior understandings, agreements, or representations by or among the parties hereto, written or oral, to the extent they
relate in any way to the subject matter hereof or the transactions contemplated hereby. This Letter Agreement may not be changed, amended,
modified or waived (other than to correct a typographical error) as to any particular provision, except by a written instrument executed
by all parties hereto.


 






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14. No
party hereto may assign either this Letter Agreement or any of its rights, interests, or obligations hereunder without the prior written
consent of the other parties. Any purported assignment in violation of this paragraph shall be void and ineffectual and shall not operate
to transfer or assign any interest or title to the purported assignee. This Letter Agreement shall be binding on each Insider and their
respective successors, heirs and assigns and permitted transferees.


 


15. Nothing
in this Letter Agreement shall be construed to confer upon, or give to, any person or corporation other than the parties hereto any right,
remedy or claim under or by reason of this Letter Agreement or of any covenant, condition, stipulation, promise or agreement hereof. All
covenants, conditions, stipulations, promises and agreements contained in this Letter Agreement shall be for the sole and exclusive benefit
of the parties hereto and their successors, heirs, personal representatives and assigns and permitted transferees.


 


16. This
Letter Agreement may be executed in any number of original or facsimile counterparts and each of such counterparts shall for all purposes
be deemed to be an original, and all such counterparts shall together constitute but one and the same instrument.


 


17. This
Letter Agreement shall be deemed severable, and the invalidity or unenforceability of any term or provision hereof shall not affect the
validity or enforceability of this Letter Agreement or of any other term or provision hereof. Furthermore, in lieu of any such invalid
or unenforceable term or provision, the parties hereto intend that there shall be added as a part of this Letter Agreement a provision
as similar in terms to such invalid or unenforceable provision as may be possible and be valid and enforceable.


 


18. This
Letter Agreement shall be governed by and construed and enforced in accordance with the laws of the State of New York without giving effect
to conflicts of law principles that would result in the application of the substantive laws of another jurisdiction. The parties hereto
(i) all agree that any action, proceeding, claim or dispute arising out of, or relating in any way to, this Letter Agreement shall be
brought and enforced in the courts of New York City, in the State of New York, and irrevocably submit to such jurisdiction and venue,
which jurisdiction and venue shall be exclusive and (ii) waive any objection to such exclusive jurisdiction and venue or that such courts
represent an inconvenient forum.


 


19. Any
notice, consent or request to be given in connection with any of the terms or provisions of this Letter Agreement shall be in writing
and shall be sent by express mail or similar private courier service, by certified mail (return receipt requested), by hand delivery or
facsimile transmission.


 


20. This
Letter Agreement shall terminate on the earlier of (i) the expiration of the Lock-up Periods or (ii) the liquidation of the Company; provided,
however, that paragraph 4 of this Letter Agreement shall survive such liquidation.


 


[Signature Page Follows]


 






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	 	Sincerely,  
	 	 
	 	Alan J. Carr 
	 	 
	 	By:	/s/ Alan J. Carr
	 	 	Name:	Alan J. Carr
	 	 	Title:	Director
	 	 	 	 
	 	William L. Transier
	 	 
	 	By:	/s/ William L. Transier
	 	 	Name:	William L. Transier
	 	 	Title:	Director


 


Acknowledged and Agreed:


 


	M3-BRIGADE ACQUISITION III CORP.	 
	 	 
	By: 	/s/ Mohsin Meghji	 
	 	Name: 	Mohsin Meghji	 
	 	Title:	Executive Chairman of the Board of Directors	 


 


 


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