The move will create the UK’s biggest temporary accommodation solutions business with a fleet of 82,000 units and 38 branches.
Mobile Mini UK has 375 employees and an annual revenue of approximately £80m.
The transaction, which is subject to UK regulatory approval, is expected to close in the first quarter of next year.
Algeco – which was formerly known as Elliott Group – is part of European modular services and infrastructure giant Modulaire.
Mark Higson, Group Chief Executive Officer of Modulaire Group, said: “Mobile Mini is a strong, strategic fit for Algeco and the combination of the two companies will drive significant value for customers.
“It will help us further deliver the Algeco Vision to be the clear market leader in modular and temporary accommodation, operating as a trusted solutions adviser to customers.”