Local government body Transport for London (TfL) has signed a pre-let with Lend Lease and London Continental Railways (LCR) to occupy a building at The International Quarter in Stratford, London.
The commercial leasing agreement has been signed as a part of the second stage of the £2.1bn development.
Australian property and infrastructure firm Lend Lease and its joint venture partner LCR are the developers for the new business in East London.
TfL will be occupying an office that has 260,000ft² of space and has been designed by Rogers Stirk Harbour & Partners (RSHP) in co-ordination with Vogt Landscape Architects.
TfL Finance managing director Steve Allen said: "We are consolidating our office accommodation into a smaller number of larger buildings.
"The International Quarter in Stratford provides the ideal opportunity for us to make further progress with its excellent transport links while enabling us to achieve significant savings."
Detailed planning consent has been secured for the building, with construction expected to start later this year.
RSHP senior partner and lead designer Ivan Harbour said: "Our tailored approach to the building design creates efficiency, continuity and coherency across the site whilst offering bespoke solutions to meet the specific needs of occupiers.
"This, together with a similarly coherent ground plane, characterises the neighbourhood as a core piece of the emerging city quarter, whilst the focus on daylight, views, connectivity, community spaces and public realm produces truly cutting-edge workplaces with people at their heart."
Lend Lease International Operations CEO Dan Labbad said: "Securing TfL as a major pre-let marks the emergence of a new generation of offices in East London that will make a lasting contribution to the local economy.
"Drawing on Lend Lease's international experience and working in partnership with LCR, our ambition is to create the most agile, healthy and efficient workplaces in the capital."
Lend Lease and LCR are seeking other major tenants for moving in to the commercial property which covers an area of four million ft².
LCR chief executive David Joy said: "The International Quarter will be a major new employment hub in East London, creating more than 25,000 jobs in total, and we have been working closely with Lend Lease to make this happen.
"Securing the first commercial tenant is a testament to the exceptional commercial environment we are delivering as part of the scheme and can only serve as a catalyst to attract further major employers to the area."