A specialist insurance company has announced plans to move to new multi-million pound headquarters at Gloucester Docks.
Ecclesiastical Group Insurance agreed the deal with the South West Regional Development Agency (SWRDA), which owns the land at Southgate Moorings.
An Ecclesiastical spokesman said designs could now be developed and planning permission sought.
The city's urban regeneration company said the news was a "massive boost".
The company, which employs about 600 staff, is currently based in Brunswick Road in the city.
Graham Johnson, from Ecclesiastical, said it hoped the move "sends a clear message to the city that we are committed to Gloucester for the long-term".
Peter Holloway, from SWRDA, said: "Not only does this secure the future of a major employer in Gloucester, but the new office building will complete one of the remaining plots at the docks - an area which we have worked hard to regenerate over the last 10 years."
Chris Oldershaw, from the Gloucester Heritage Urban Regeneration Company, said it started working with Ecclesiastical on the move in 2007.
The location, which is currently a temporary car park, was decided on following a consultation with staff.
Mr Oldershaw said: "Working with Ecclesiastical, and with the support of the South West RDA, we were able to put together a deal which enabled Ecclesiastical to stay in the heart of the city, rather than lose one of our major employers."