By Sagarika Jaisinghani May 20 (Reuters) - The UK's FTSE 100 retreated on Wednesday as data showed inflation fell to its lowest since August 2016 in the latest economic blow from the coronavirus outbreak, with investors also digesting another mixed bag of quarterly earnings reports. UK homebuilder Vistry Group Plc VTYV.L shed 3.2% on forecasting more job cuts as it consolidates the operations of Bovis Homes and construction company Galliford Try's GFRD.L residential units. The blue-chip FTSE 100 .FTSE was down 0.2%, with the banking index .FTNMX8350 tumbling 1.2% on increased bets of negative interest rates.