Tower 42, which was the first skyscraper to be built in the City of London, is now being put up for sale by the owners BlackRock and Hermes Real Estate.
After owing the property for 12 years the owners have now announced plans to sell the 600ft building, which was the former Natwest tower.
They also have plans to sell five other office buildings, in the same area, on a 2.2-acre plot.
The tower opened in 1980 as a headquarters for the Natwest Bank, and since then has remained the tallest occupied building within the City of London.
The tower, which is situated a short distance from Liverpool Street station and the Bank of England, has been given a £300million price tag by Jones Lang LaSalle (JLL) real estate experts.
JLL will be marketing and selling the property for BlackRock.
It is thought that the valuation is so high because of the weak value of the pound in recent months and the high demand for high quality office space in central London.
Marcus Sperber, the BlackRock managing director, said, “With the expectation of future returns, combined with a dearth of trophy assets on the market and weak sterling, the partners believe that the timing is right to market the asset.”
Due to the demand for office space in the city, Tower 42 is expected to only be on the market for a short while. This is because serious buyers are thought to make themselves known very quickly.