Indicate
by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.
Form 20-F [ ] Form 40-F [X]
Pursuant
to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.

SIGMA LITHIUM ANNOUNCES
FULL RESUMPTION
OF MINING-INDUSTRIAL OPERATIONS; SIGNED
A TAC AGREEMENT WITH THE STATE OF MINAS GERAIS;
EXPECTS TO PRODUCE 240,000t WITHIN 12 MONTHS
___________________________________________________________________________________________________________________
HIGHLIGHTS
| • | The
Company’s industrial and mining operations returned to being fully back online following the signature of a TAC Agreement. |
| • | Sigma
Lithium remains focused on ramping up mining operations
and advancing its expansion plans, as per its 2Q 26 announcement: |
| ○ | 240,000t of lithium oxide concentrate within 12 months; and |
| ○ | 330,000t production in FY 27. |
| • | The
Company has greenlighted the next stage of upgrades
of the haulage fleet in cooperation with their manufacturer SANY. |
| ○ | Expects to increase fleet haulage capacity with 75t trucks and 98t excavators. |
___________________________________________________________________________________________________________________
Toronto, August 21, 2026
– Sigma Lithium Corporation (NASDAQ: SGML, TSX-V:SGML BVMF: S2GM34) (“Sigma Lithium” or the “Company”),
the largest producer of lithium oxide concentrate in the Americas¹ and dedicated to industrializing lithium materials to supply
global producers of batteries for energy security in a responsible manner, announces that it has signed a Terms for Adjustment of Procedures
agreement (“Termo de Ajuste de Conduta” or “TAC Agreement”) with the State of Minas Gerais.
MINING AND
INDUSTRIAL OPERATIONS FULLY BACK ONLINE
Following the signing of the
TAC Agreement, Sigma Lithium’s mining and industrial operations are fully back online, with the Company resuming its regular
operating activities.
The Company remains focused
on ramping up mining operations and advancing its expansion plans, as per its 2Q 26 announcement:
| • | | 240,000t of lithium oxide concentrate within 12 months; and |
| • | | 330,000t production in FY 27. |
Operations related to the sale
of high-purity lithium fines consisting of reprocessed tailings, as well as other intermediate grade products, continued without disruption
throughout the partial suspension of operations.
The signing of the TAC Agreement
reflects Sigma Lithium’s continued engagement with Minas Gerais State authorities and the Company’s unwavering commitment
to operating under the highest environmental and regulatory global framework in the Vale do Jequitinhonha, producing the Quintuple Zero
Lithium. During negotiations, Minas Gerais environmental authorities reviewed an extensive amount of factual and quantitative environmental
technical documentation provided by the Company.
Sigma Lithium estimates that
the execution of the adjustments of environmental procedures under the TAC Agreement will require capex of approximately US$1,000,000.
The Company agreed to the payment of up to US$540,000 for certain fines, related to environmental matters dating from 2013 to 2022.
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Sigma Lithium vehemently
denies any wrongdoing with respect to the key claims raised in connection with the Company’s operations and reaffirms that the
Company:
| • | | has not misrepresented information filed with environmental authorities since 2018; |
| • | | has not commercially sold lithium materials prior to May 2023; and |
| • | | denies claims alleging that two houses located outside Sigma Lithium’s licensed
area have been negatively impacted by its activities. Nevertheless, the Company agreed to widen and gravel their access roads, as
part of the TAC Agreement. |
TAC AGREEMENT BACKGROUND
A TAC Agreement is a standardized
form of agreement between regulators and corporates in Brazil. It translates into “terms for adjustment of procedures”. The
adjustments of procedures must be mutually agreed between the regulatory body (federal or state) and the company. A significant majority
of publicly traded companies in Brazil have TAC Agreements with various regulators (both federal and state), which are used to resolve
corporate and environmental matters, as a TAC Agreement provides legal certainty for the company by clearly outlining actions to be undertaken
and deadlines for their execution.
QUALIFIED PERSON
The qualified person (QP) for
the technical information contained herein is Mr. Alexandre Rodrigues Cabral, P. Eng., member of the Ordre des Ingenieurs du Quebec (OIQ,
membership number 105796), who is considered, by virtue of his education, experience and professional association, a Qualified Person
under the terms of NI 43-101. Mr. Cabral is not considered an independent QP under NI 43-101 as he is a Sigma Lithium Director and Chair
of the Company’s Technical Committee. Mr. Alexandre Rodrigues Cabral has reviewed and approved the technical and scientific content
of this release.
ABOUT SIGMA LITHIUM
Sigma Lithium Corporation (NASDAQ:
SGML, TSXV: SGML, BVMF: S2GM34), (“Sigma Lithium” or “the Company”) is the largest producer of lithium oxide concentrate
in the Americas¹ and dedicated to industrializing socially and environmentally sustainable lithium materials to supply global producers
of batteries for energy security.
The Company runs one of the
world’s largest lithium production sites—the fifth-largest industrial-mineral complex for lithium oxide concentrate—at
its Grota do Cirilo operation in Brazil. Sigma Lithium is at the forefront of environmental and social sustainability in the electric
battery materials supply chain. The Company’s Cleantech Industrial Plant combines the reuse of 100% of water, zero use of toxic
chemicals, zero tailings and the use of 100% renewable electricity. For more than two years Sigma Lithium has not experienced an accident
with lost time.
Sigma Lithium currently has
a nameplate capacity to produce 330,000 tonnes of lithium oxide concentrate on an annualized basis at its mine and state-of-the-art Cleantech
Industrial Plant. The Company has initiated a Phase 2 expansion designed to close to double annual production capacity to 580,000 tonnes
and plans a Phase 3 expansion to increase this further to 830,000 tonnes. For more information about Sigma Lithium, visit our website
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FOR ADDITIONAL INFORMATION PLEASE
CONTACT
Anna Hartley,
Vice President of Global Banking and Investor Relations
anna.hartley@sigmalithium.com.br
+44 7866 458 093
Mariana Bengtson,
Investor Relations Manager
mariana.bengtson@sigmalithium.com.br
+55 11 9 2144 2750
Sigma
Lithium
 |
Sigma Lithium |
 |
@sigmalithium |
 |
@SigmaLithium |
FORWARD-LOOKING
STATEMENTS
This
news release includes certain “forward-looking information” under applicable Canadian and U.S. securities legislation, including
but not limited to statements relating to timing and costs related to the general business and operational outlook of the Company, the
environmental footprint of tailings and positive ecosystem impact relating thereto, donation and upcycling of tailings, timing and quantities
relating to tailings and Green Lithium, achievements and projections relating to the Zero Tailings strategy, achievement of ramp-up volumes,
production estimates and the operational status of the Grota do Cirilo Project, and other forward-looking information. All statements
that address future plans, activities, events, estimates, expectations, or developments that the Company believes, expects, or anticipates
will or may occur is forward-looking information, including statements regarding the potential development of mineral resources and mineral
reserves which may or may not occur. Forward-looking information contained herein is based on certain assumptions regarding, among other
things: general economic and political conditions; the stable and supportive legislative, regulatory and community environment in Brazil;
demand for lithium, including that such demand is supported by growth in the electric vehicle market; the Company’s market position
and future financial and operating performance; the Company’s estimates of mineral resources and mineral reserves, including whether
mineral resources will ever be developed into mineral reserves; and the Company’s ability to operate its mineral projects including
that the Company will not experience any materials or equipment shortages, any labor or service provider outages or delays or any technical
issues. Although management believes that the assumptions and expectations reflected in the forward-looking information are reasonable,
there can be no assurance that these assumptions and expectations will prove to be correct. Forward-looking information inherently involves
and is subject to risks and uncertainties, including but not limited to that the market prices for lithium may not remain at current
levels; and the market for electric vehicles and other large format batteries currently has limited market share and no assurances can
be given for the rate at which this market will develop, if at all, which could affect the success of the Company and its ability to
develop lithium operations. There can be no assurance that such statements will prove to be accurate, as actual results and future events
could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking
information. The Company disclaims any intention or obligation to update or revise any forward-looking information, whether because of
new information, future events or otherwise, except as required by law. For more information on the risks, uncertainties and assumptions
that could cause our actual results to differ from current expectations, please refer to the current annual information form of the Company
and other public filings available under the Company’s profile at www.sedarplus.com.
Neither the TSX Venture Exchange
nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for
the adequacy or accuracy of this news release.
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