City A.M. understands Canary Wharf Group has approached agents to sell its 15 per cent stake in 20 Fenchurch Street.
In April last year it was reported that Morgan Stanley, which bought 35 per cent a share alongside the China Investment Corporation (CIC) and the Qatar Investment Authority in 2010, was planning to sell its share. It is understood all three are considering their options. In total, the 50 per cent stake, which Canary Wharf Group still manages, could be valued at £600m.
The news comes just weeks after British Land and Oxford Properties sold the Cheesegrater, just around the corner, for £1.15bn. Originally, only British Land planned to sell its 50 per cent share, but Oxford Properties was persuaded by the buyer, CC Land, to part with its share.
If the Walkie Talkie's other owner, Land Securities, chooses to do the same, that would value it at £1.2bn.
The building's new owners will get 688,000 sq ft of office space, currently fully let to companies including insurer RSA, plus their own "green space", the ever-popular Sky Garden, which includes one of the capital's highest open-air terraces.
Bloomberg has reported CIC is considering a bid.
Both Land Securities and Canary Wharf Group declined to comment.