The Los Bronces–Andina Alliance: a unique mining joint venture in Chile
Shawn Sarsfield Doyle
McCarthy Tétrault, Santiago
In 2025, Anglo American and Codelco announced the Bronces–Andina alliance, a first-of-its-kind partnership which fully integrates two major copper mines – owned by different companies – into a single coordinated operation without merging their ownership. This innovative structure allows Anglo American’s Los Bronces mine and Codelco’s Andina mine to be run under one unified mine plan, unlocking significant extra value and production that neither could achieve alone. The two mines are located adjacent to each other in the Chilean Andes. Compared to typical mining joint ventures in which partners jointly own one project or deposit, the Los Bronces–Andina Alliance stands out for combining two already-operating, separately owned mines into a jointly managed ‘mining district’. Each company retains full ownership of its own assets, yet the two companies will share the planning, risks, costs, and additional output of their joint operation equally under an operational framework. This arrangement is widely considered unprecedented in the mining industry, particularly as a collaboration between a private multinational (Anglo American) and the Chilean state copper company (Codelco).
Ownership structure and governance
The key feature of the new alliance is that each company maintains full ownership of its mine, facilities, and mineral concessions. Anglo American’s subsidiary, Anglo American Sur (AAS) continues to own and operate Los Bronces, and Codelco continues to own Andina – there is no transfer or merger of property rights. Rather than transferring any ownership stakes, the companies formed a new operating entity jointly owned 50/50 by Anglo American Sur and Codelco. This operating company’s role is to coordinate mine planning and operations across the two sites, essentially managing Los Bronces and Andina as a single unit on a day-to-day basis.
Because the new operating entity is equally owned, governance is shared evenly. Neither Anglo American nor Codelco has a greater say in the joint operations, as decisions are made jointly, reflecting a true partnership. Codelco’s Chairman Máximo Pacheco described this governance setup as ‘a corporate governance structure equally composed of Codelco and Anglo American’, calling the public-private collaboration ‘unprecedented’ globally. This is a departure from many traditional joint ventures in which one partner might be the operator or hold a slight majority – here, operational control is genuinely mutual.
Operational integration and resource sharing
At the heart of the Los Bronces–Andina Alliance is deep operational integration across the two mines. Even though Los Bronces and Andina are run by separate companies, they are next door to each other in the Andes, tapping what is essentially a continuous mineral-rich district. In fact, the mines are so close that their workings physically interact: Anglo American’s vast Los Bronces open pit mine is situated adjacent to Codelco’s Andina operations, which include an underground mine. Underground operations have previously caused ground subsidence around the Los Bronces pit, so the two teams have had to communicate and stagger activities to manage geotechnical risks. Building on this necessity, the new alliance turns proximity from a challenge into an opportunity. By formally integrating their mine plans, Anglo and Codelco can optimise how they extract ore across the district, avoiding redundant work and improving safety and efficiency for both mines.
Specifically, the joint mine plan allows Los Bronces and Andina to operate as if they were one large mine. This means, for example, they can adjust which mine expands or produces at a given time based on whose ore is more accessible or whose facilities have capacity, rather than each sticking to a siloed schedule. The companies have stated that this coordination will unlock an additional 2.7 million tonnes of copper over 21 years (once the plan kicks in around 2030) that would not be mined otherwise. That averages to about 120,000 extra tonnes per year of copper (a 20 per cent boost relative to their combined 2024 output) purely from synergy – a very tangible gain. Remarkably, this is achieved ‘with minimal incremental capital expenditure’. In other words, there is no need to build major new processing plants or infrastructure; instead, better use will be made existing facilities through strategical planning. This is a major difference from typical mine growth projects which often require billions in new investment for new mills, pits, or waste areas. Here, this is avoided through the pooling of resources.
A major source of efficiency is the coordination of processing capacity and infrastructure. The two mines already each have processing plants (concentrators) and extensive infrastructure such as roads, pipelines, tailings storage, etc. Under separate operation, each might have either unused capacity or insufficient capacity at times. Now, as an integrated district, they can treat one mine’s ore using the other’s plant if needed, share excess conveyor/pipe capacity, and jointly plan waste disposal or water use.
This kind of resource sharing is uncommon in mining. Usually, even neighbouring operations compete for productive resources or at best sign limited agreements such as toll-milling agreements to process each other’s ore on occasion. Here there is a holistic integration of operations. As a result, the alliance expects to achieve about 15 per cent lower unit production costs compared to running Los Bronces and Andina independently. This represents a huge efficiency gain in an industry where single-digit percentage cost improvements are notable. It essentially propels these mature mines into a new league of competitiveness by eliminating redundancies and leveraging economies of scale together.
Another aspect of operational integration is joint use of the mineral deposit itself. The contract allows the mining of areas which may straddle the boundary of Los Bronces and Andina in the most logical way for the resource, without worrying about ‘whose side’ the ore is on. This can reduce ore left in the ground. While specific technical details are not public, industry experts note that coordinating two adjacent ore bodies can prevent situations where an optimal pit design is curtailed at the property line or where two separate underground developments might interfere. By acting as one, the geology can be developed optimally for maximum recovery. This is one reason the alliance is said to ‘unlock the full value of this world-class mining district’ that neither company could fully realise alone.
Financial outcomes
The strategic drive behind the Los Bronces–Andina alliance is to enhance productivity and value significantly in an era where large new copper discoveries are rare. Both Anglo American and Codelco recognise that these neighbouring mines contain enormous resources (about 60 million tonnes of copper in situ, among the largest copper endowments globally). However, each faced diminishing returns and constraints when operating separately – Los Bronces had complex community and environmental limits on further expansion, and Andina is an aging operation with infrastructure limitations. By teaming up, their shared goal is to unlock at least US$5bn in additional pre-tax net present value (NPV) beyond business-as-usual. This figure, vetted in their joint studies, comes from the extra 2.7 million tonnes of copper produced at lower cost over the 21-year plan. This US$5bn uplift is split 50/50 between Anglo (AAS) and Codelco.
Setting a new benchmark
This new alliance is likely to serve as a new industry benchmark for collaboration and innovation in mining. Both companies have cast the alliance as transformative. Anglo American’s statement calls it ‘a transformative development in the global copper industry’ that sets ‘a new benchmark for innovation, efficiency, and sustainability in mining operations’. This signals an intent that beyond the immediate financial upsides, Anglo American sees value in pioneering a model that could be replicated elsewhere.
The Chilean Mining Association (SONAMI) also publicly welcomed this alliance, noting that ‘clustering projects into [shared] mining districts’ could become a way to streamline permitting and development in the future. In other words, the industry is watching this as a potential blueprint: if two operators can coordinate rather than each bulldozing separate roads, building duplicate facilities and competing for water and community resources, then perhaps mining can be carried out more sustainably and efficiently through such partnerships.
In the future, mining lawyers around the world will likely refer to this alliance as the original precedent for a new type of joint venture.