"One or two" leases have been signed for office space at the Shard, according to developer Irvine Sellar, but the tenants have not yet been named.
Mr Sellar told Kay Burley on LBC 97.3 that he is confident that both the Shard and the adjacent building called The Place will be fully leased by the end of 2014.
Setting out the timetable for the occupation of the European Union's tallest building, Mr Sellar said: "On February 1 the viewing gallery will open; around about April the restaurants will open; [hotel operator] Shangri-La plan to open in May – but it could slip to June – and the offices will open as we lease them – and we do have one or two leases now in place for the offices."
589,602 sq ft of office space is available up to level 28 of the Shard. Nearly a third of the space was pre-let to Transport for London but its lease was bought out by Sellar and the tower's Qatari backers in 2010.
Asked about criticism of the state of Qatar's involvement in such a large UK infrastructure project, Mr Sellar said: "All I say is the Qataris have done a brilliant job in backing this in probably one of the worst recessions we can remember. I think London will owe a great deal to Qatar.
"This is a building that every Londoner will be able to visit to view the viewing galleries, eat in the restaurants, sleep in the hotel and work in the offices.
"This is a building Londoners will own and they should thank our relationship with Qatar for making it possible."
And just how much will it cost to live in the apartments near the top of the Shard? Sellar is remaining tight-lipped: "We're not quoting prices, but I think they will break some records."