Grosvenor Fund Management has predicted a sharp recovery in London office returns starting in 2010 and generating 12-13% per annum returns over five years. This follows capital value declines in excess of 45% since mid-2007. Rents are expected to increase by about 60% from their trough through 2011-2016, Grosvenor said. Supply is expected to be very constrained: 2009-2013 will see the lowest level of new offices delivered in London's West End and the City since records began in 1986.