Berkeley Homes bought the bulk of the Borough Triangle site bounded by Newington Causeway, Borough Road and the railway line from housing association Peabody in 2020.
In 2022 Berkeley Homes submitted a planning application for 838 homes in buildings of up to 46 storeys.
Last year Berkeley Homes bought the Institute of Optometry site on Newington Causeway for £4.5 million.
The company this week held two public exhibitions of revised proposals - by architects Macreanor Lavington - which it intends to submit to Southwark Council in a fresh planning application this spring.
Under the new plans, the tallest tower - at 44 storeys - would be located on the Institute of Optometry site, with a 38-storey block planned for the Borough Road side of the triangle.
Overall, the scheme would incorporate around 900 homes, with 230 affordable homes, of which 156 would be offered under 'social rent' tenure.
Berkeley Homes says it hopes to keep Mercato Metropolitano on the site: "We are continuing to have constructive conversations with Mercato about this.
"We are proposing around 30,000 sq ft of modern, high-quality space for them at the centre of the site, with outside spill-out areas for relaxing and dining."
Berkeley says its revised scheme has been influenced by a variety of factors, including its acquisition of extra land, new requirements for second staircases in tall buildings, increased building costs and "foreign events".
In its latest published accounts the Institute of Optometry says it has been given a nil-rent lease to remain in its current building for up to two years while it searches for new premises.