Aviva Plc has kicked off the search for a partner to help fund a planned new skyscraper in the heart of the City of London’s insurance district, as it aims to tempt investors willing to make a bold bet that office rents are set to soar.The insurer’s investment management arm has appointed broker Knight Frank to sell a stake in the 130 Fenchurch Street project, people with knowledge of the process said. A deal could pave the way for a start on the development, which secured planning planning approval in Sept ...