Southern Water has secured a further £300 million of equity investment, delivering the £1.2 billion equity support package announced in July 2025.
The latest investment takes total equity invested in Southern Water to £2.8 billion since Macquarie Asset Management's acquisition of the company in 2021.
The new investment comes from a consortium led by Macquarie Asset Management (MAM), alongside Asterion Industrial Partners (AIP), an independent European infrastructure investment manager headquartered in Madrid with approximately $10 billion of assets under management. AIP will provide the majority of the new capital, becoming a minority shareholder in the company.
This latest investment delivers in full the £1.2 billion equity support package announced in July 2025 and brings total equity invested in Southern Water to £2.8 billion since MAM acquired the business in 2021. No dividends have been paid to shareholders during this period..
The proceeds of the equity funding will support Southern Water's record £8.5 billion investment programme for AMP8.
In the first year of the 2025-30 AMP8 period (year ended 31 March 2026), Southern Water said it has continued to make progress against its operational turnaround, delivering improvements across a number of measures – including water supply interruptions, leakage and external sewer flooding – alongside a record level of capital investment in its network.
Lawrence Gosden, Chief Executive Officer of Southern Water, said:
"Over the past four years, we’ve worked hard to transform Southern Water, improving operational performance while significantly increasing investment in the services and infrastructure our customers rely on every day. We’re seeing the benefits of that progress, but we remain focused on the substantial work still ahead.
"This additional equity support enables us to build on that momentum as we deliver our ambitious £8.5 billion investment programme over the next five years. It’ll help us improve services for customers, strengthen the resilience of our infrastructure and continue reducing our environmental impact.
"We’re grateful for the continued support of Macquarie, whose long-term investment and industrial expertise have been instrumental in supporting our turnaround. We’re also pleased to welcome Asterion Industrial Partners as a new shareholder. Their investment represents a strong endorsement of the progress we’ve made and confidence in our plans for the future.”
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