London & Regional and Chelsfield are considering selling a stake in their £1.3 billion Elizabeth House project next to Waterloo station.
The project will be an office-led 130,000sq m development known as One Waterloo. And the site at 39 York Road is expected to be valued by potential investors up to £300 million.
The scheme has planning permission for two main buildings, one of 29 and 14 storeys and the other of 11 storeys. Proposals also include 142 flats.