June 15 (Reuters) - Wells Fargo & Co Chief Financial Officer Mike Santomassimo said on Tuesday that the bank is standing by its previous guidance that net interest income for 2021 will be flat-to-down 4% from the annualized level seen in last year"s fourth quarter. Speaking at an investor conference held virtually, Santomassimo said that for the bank to achieve the middle of that range it needs to see flat loan totals. "Overall loans are down right now, so we will see how that shakes out," he said.