LONDON, June 9 (Reuters) - Rising cases in Britain of the Delta variant of COVID-19 first detected in India discouraged investors from buying UK-focused equity funds in May, data from fund network Calastone showed on Wednesday. Flows into UK equity funds slowed to 147 million pounds ($208 million) from 335 million pounds in April and 572 million in March, with inflows switching to outflows from the middle of May as infection rates rose, Calastone said in a statement. The drop-off in enthusiasm came after “a lot of hope has been baked into UK-focused equity funds since the end of January as the rapid vaccine rollout raised hopes of release from COVID restrictions”, said Edward Glyn, head of global markets at Calastone. Investors also ditched real estate funds due to the uncertainty, with the sector seeing outflows of 445 million pounds in May, the second-worst on record. British insurer Aviva in May said it would close three UK property funds which had been frozen since March 2020 due to market turmoil caused by the pandemic. More than two-thirds of UK-based fund flows by value pass across the Calastone network each month. $1 = 0.7078 pounds Reporting by Carolyn Cohn Editing by Bernadette Baum Our Standards: The Thomson Reuters Trust Principles.