The developer will submit plans to Islington Council for the Kohn Pedersen Fox designed building at 99 City Road within the next few weeks.
The site is presently the headquarters of satellite communications group Inmarsat, which is planning to vacate the existing 1980s office building at the site.
This building will be partially demolished with around 60% of the existing building structure retained to reduce concrete use and shorten the construction programme.
The planned replacement tower will rise to around 160m and widen the pedestrian area around the site. It will also introduce green terraces and a winter garden at street level.