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
SIGNS WITH A MAJOR BRAZILIAN BANK A US$100 MILLION COLLATERALIZED BANK GUARANTEE
___________________________________________________________________________________________________________________
SUMMARY
| · | Sigma Lithium
signs a US$100 Million bank guarantee (“Bank Collateral”), fully collateralized by its clients through a blend of corporate
guarantees, letters of credit and export receivables to be mutually agreed. |
| · | This is a key
milestone for the Company to execute its growth plans in 2026 and finalize the construction of its second Greentech industrial plant to
double its production capacity from 270,000t to 520,000t annually. |
| · | The Bank Collateral
enables Sigma Lithium to access development bank financing made available to the Company. |
| · | Sigma Lithium
is the engine of growth of Vale do Jequitinhonha, employing 13,000 people directly and indirectly, while benefitting an additional
21,000 people through its social inclusion programs. |
| o | The Expansion will
further promote the continuous economic growth of the Jequitinhonha Valley through a proportional increase in both employment and social
inclusion beneficiaries. |
| o | 10
years ago, before the Company became the largest lithium industrial mineral producer in the Americas, the region was the second poorest
in the country and currently it grows by over 10% annually. |
São
Paulo, April 2, 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 socially
and environmentally sustainable lithium materials to supply global producers of batteries for energy security, announces the signing of
an US$100 million collateralized bank guarantee with a major Brazilian bank. The bank guarantee (“fiança bancária”)
is to be collateralized by its clients, through
a blend of corporate guarantees, letters of credit and export receivables to be mutually agreed amongst the parties.
The bank guarantee
will support the construction and installation of Sigma Lithium’s Greentech Industrial Plant 2, increasing the Company’s nameplate
annual production capacity of high-grade premium lithium oxide concentrate from 270,000 tonnes to 520,000 tonnes. Sigma Lithium’s
Greentech Industrial Plant 2 will replicate the same environmentally sustainable technologies and processes currently used in the Company’s
operating Greentech Industrial Plant 1.
The Bank Guarantee
is subject to, amongst other typical terms and conditions, the completion of the negotiation of definitive written agreement(s) with all
the parties, which are to be consistent with the agreed terms contained in the preliminary agreement signed in the letter of intention
.
Ana Cabral, Co-Chairperson
of Sigma Lithium, said: “The support from our banking partners in Brazil and global clients for our lithium oxide underscores
the strength of these relationships, the competitiveness of our industrialized product and their confidence in our management team and
business strategy.
Ms. Cabral added: “Furthermore,
this expansion reinforces our commitment to fostering sustained economic growth and prosperity in the communities of the Jequitinhonha
Valley. Since Sigma Lithium´s initial investments in the region dating back to 2012, when it was still a private company, we have
dreamed of transforming the future of our neighbors in this historically impoverished region through the successful implementation of
a globally competitive lithium industry. That prosperity became a reality 14 years later, driven by the significant economic development
generated by the Company´s shareholders investments in building and implementating the fifth-largest global lithium industrial-mineral
complex in the Vale do Jequitinhonha, now the largest producer in the Americas of industrialized lithium oxide”
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. 
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 operates 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 Greentech Industrial Plant combines dry stacking, the reuse of 100% of water, zero
use of toxic chemicals 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 270,000 tonnes of lithium oxide concentrate on an annualized basis (approximately 38,000–40,000
tonnes of LCE) at its mine and state-of-the-art Greentech Industrial Plant. The Company has initiated a Phase 2 expansion designed to
close to double production capacity to 520,000 tonnes. For more information about Sigma Lithium, visit our website
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 |
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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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