The City of London's infamous 'Walkie Talkie' tower is finally full

20 Fenchurch Street, otherwise known as the "Walkie Talkie" building, has finally leased all of its space, according to the Evening Standard.

The Chartered Institute of Securities and Investments (CISI) will be taking over the last remaining lease on the third floor of one of London's most visually striking skyscrapers.

It comes six years after Canary Wharf Group & Land Securities agreed a £500 million ($706 million) joint venture to build the 150 metre-high tower - one of a series of major building projects in City of London after the financial crisis of 2008.

The Standard notes that the skyscraper has been locked in a war over attracting tenants with the neighbouring Leadenhall Building - nicknamed the "Cheesegrater" - which was exacerbated by a "sluggish" economy after the economic crash.

It quotes one insider as saying "When Land Securities said they were going to do this in 2010, a lot of the City analysts stood up and said they were mad. But they - and British Land - have been completely vindicated."

The Walkie Talkie tower made headlines in 2013 when sun rays reflected off its curved windows and melted parts of a car parked nearby. The developers agreed to pay for repairs and cover the windows until construction was complete. It has also been criticised for its aesthetics, and won the Carbuncle Cup for Britain's worst new building in September 2015.

However, the free to enter "Sky Garden" that opened on the top floor in January last year has proved to be a hit with Londoners and tourists alike. As well as lush plant decorations, it has a "Skypod" bar, as well as a more upmarket seafood grill restaurant on separate levels.