The owner of the Gherkin has appointed agents to advise on the sale of the skyscraper after receiving several unsolicited bids. Safra Group has instructed GM Real Estate to advise on any bids that come in for the 516,000 sq ft trophy building. It is understood it would take a monumental bid of more than £1bn for Safra to consider a sale.Last month, it received a bid from Hong Kong-headquartered soy sauce manufacturer Lee Kum Kee but discussions with the party are not ongoing.Safra bought the iconic landmark building three years ago for £700m and has since moved the rents on considerably.