Land Securities is in exclusive negotiations with Canary Wharf Group to build the Rafael Vinõly-designed Walkie-Talkie tower for £350m, it has emerged

The pair have declined to confirm weekend media reports of an imminent deal over the 56-storey development, but Building understands one is likely in the next four-to-five weeks. Construction may start as early as September.

The news will come as a blow to contractors bidding for the job, known officially as 20 Fenchurch Street, as Canary Wharf Group (CWG) is almost certain to use its in-house contracting arm to build the tower.

CWG is likely to buy a stake in the project, as it did with Drapers Gardens, its first significant development in the City of London. It took a 25% stake in that scheme and was appointed development manger and lead contractor, before selling its stake to New York investment manager BlackRock after construction.

Land Securities said it “was in conversation” over the tower, but declined to confirm that talks with CWG were exclusive.

Last month British Land announced it was talking to partners about taking a stake in the “Cheesegrater” tower on 122 Leadenhall Street to allow construction to start.