The InfraRed investment is equal to that of Prudential. Full equity funding from two British institutions has also been confirmed.
Capable of generating 500GWh of electricity every year for 120 years, the project will meet the power requirements of Swansea Bay region, which includes the city and county of Swansea and Neath Port Talbot.
InfraRed Capital Partners chief executive Werner von Guionneau said: "We are proud to be playing a key role in securing the future of this world-leading renewable energy project.
"The power station is unique in that it not only leverages the estuary’s second highest tidal range in the world but it will also make a material contribution towards both the local economy in South Wales and the long term stability of sustainable energy supply in the UK."
The tidal power station is expected to reach a financial close in the summer following which construction will be commence immediately. This is expected to create approximately 2,000 jobs.
Tidal Lagoon Power chief executive Mark Shorrock said: "The Swansea Bay Tidal Lagoon provides a scalable blueprint for a UK-led global industry that delivers true value to the nation."
