Chile signs definitive CEOL for Salar de Maricunga with Codelco–Rio Tinto joint venture

Mechanism

The Salar de Maricunga CEOL definitivo is the second major operational instrument implementing Chile's April 2023 National Lithium Strategy. While the Salar de Atacama tranche (NovaAndino Litio, closed December 2025) is a legacy-contract restructuring of the world's lowest-cost producing brine, Maricunga is a greenfield development requiring full capital mobilisation.

Structural features confirmed by the Codelco announcement:

1. Vehicle. Salar de Maricunga SpA — a wholly owned Codelco subsidiary — is the CEOL holder and contracting party. The state majority is structural, not a "golden share" mechanism as in the Atacama JV: Codelco holds majority interest. 2. Rio Tinto as strategic partner. Following a competitive tender launched after the 2023 strategy, Rio Tinto was selected in May 2025. The definitive CEOL signed 12 February 2026 formalises its participation with a capital contribution of up to US$900 million, making Maricunga SpA one of the largest lithium greenfield commitments outside China. 3. Concession expansion. The CEOL area was extended to incorporate pre-1979 mining concessions that Codelco acquired from Lithium Power International in 2024, enlarging the resource base available to the JV. 4. Exploration extension. The original 2018 CEOL exploration phase has been extended by four years, reflecting the regulatory and capital-raising timeline. 5. Conditions precedent. Foreign competition-authority approvals (Rio Tinto is dual-listed UK/AU) projected for completion during 2026; the signing ceremony was held at La Moneda, chaired by President Boric. 6. Production targets. The project targets 15–20 kt LCE/year from 2030, scaling toward ~55 kt LCE/year by 2033 — relatively modest against Atacama's ~300 kt LCE/year, but material to the global lithium supply curve post-2030 as the market rebalances from current oversupply.

Why severity 4

The Maricunga CEOL rates severity 4 on the same basis as the parent 2023 National Lithium Strategy and the Atacama JV close: it is a large-scale, long-duration sovereign commitment locking in the state-majority development path for a strategic salar.

• Supply-curve anchor. Even at 15–55 kt LCE/year,

Maricunga extends Chile's lithium supply beyond the Atacama alone, reducing single-salar concentration risk and sustaining Chile's position as the #2 lithium producer globally.

• Capital signal. Rio Tinto's US$900m commitment is the

largest Western mining-house investment in a Chile state-led lithium vehicle and validates the public-private CEOL model the 2023 strategy established. It counters the narrative that state majority deters capital; peer governments (Bolivia, Zimbabwe, DRC) are watching closely.

• Western supply-chain diversification. Rio Tinto is an

Australian-UK vehicle; its involvement plugs Maricunga production into Western-aligned battery supply chains. This is the US IRA / EU CRM Act supply-chain diversification logic operating via a bilateral mining JV rather than a bilateral trade agreement.

• Severity is 4 not 5 because the project is still in

exploration-phase extension and full-scale production is a decade away; near-term supply-market impact is nil.

Downstream implications

• Rio Tinto (RIO): US$900m greenfield lithium exposure,

strengthening its battery-materials strategy alongside the Rincon (Argentina) and Jadar (Serbia, pending) assets; shareholder debate on lithium capital allocation will intensify as prices remain depressed in 2026.

• SQM: the Maricunga concession transfer from SQM to

Codelco (as part of the Atacama JV closing) means SQM's former Maricunga exploration rights are now under state control and partnered with a rival major — SQM has no path back to Maricunga.

• **Albemarle (ALB), Lithium Americas (LAC), Sigma Lithium

(SGML):** if Maricunga ramps as planned, the 2033 supply-curve addition at ~55 kt LCE/year competes with other greenfield projects targeting the same post-2030 demand wave.

• LIT, REMX, BATT: modest structural positive — Chilean

brine lithium is among the lowest-cost supply; a long-duration Western-aligned JV reduces China's dominant processing market share in the lithium-to-battery-grade refining chain.

• EM resource-upstream-capture theme: Chile's contractual

state-majority model with Western capital is the moderate path between Indonesia's outright export bans and Argentina's RIGI liberalisation. The CEOL definitivo makes this model institutionally durable.

Open questions

• What is Rio Tinto's exact ownership percentage in Salar de

Maricunga SpA? Codelco described it as a "strategic partner" with capital contribution; the discovery note suggests ~49.99% but the primary announcement did not confirm the split.

• Do the remaining conditions precedent (foreign competition

approvals) close in 2026 as projected, or does Australian FIRB or UK CMA review extend the timeline?

• How does indigenous-community governance (noted by Codelco)

translate into CEOL obligations — are there consent-based production limits on brine extraction volumes?

• Does the Empresa Nacional del Litio (ENL) bill still stalled

in Congress ultimately fold Maricunga SpA into a broader national lithium company, changing Rio Tinto's counterparty?