SINGAPORE (S&P Global Ratings) Aug. 19, 2020--S&P Global Ratings said today that COVID-19 woes have cast a shadow over the half-year financial results of PT Bank Mandiri (Persero) (BBB-/Negative/A-3). The Indonesian bank's performance in the first half of 2020 was broadly in line with our expectations. Net interest margins contracted by 65 basis points (bps) and provisioning costs rose 66%, resulting in a 24% decline in profit after tax compared with the first half of 2019. Return on assets fell to 1.5% on an annualized basis, from 2.2% in the first half of 2019. We expect Mandiri's return on assets to drop to about 1% in 2020 due to lower margins and higher credit costs (as measured by loan loss