The spate of downgrades of corporate debt papers by rating agencies has now hit the mutual fund industry. On Friday, Indian ratings major Crisil downgraded three liquid schemes and reaffirmed ratings on five others. All the eight schemes, belonging to five different fund houses, were given a month's notice to correct their portfolios to continue with the ratings which were assigned earlier, a release from Crisil said. ''Crisil has downgraded its credit quality ratings (CQRs) on three mutual fund schemes,'' the release said. ''The credit quality of these schemes' portfolios remains inconsistent with their previous rating of 'AAAf', even after the expiry of a curing period for correction of the mismatches,'' it added. The three schemes which were downgraded were DSP BlackRock Liquid Plus Scheme, downgraded from AAAf to AAf, ING Liquid Fund, downgraded from AAAf to Af and ING Liquid Plus Fund, downgraded from AAAf to A+f. An 'AAAf' rating on a scheme signifies that fund's portfolio provide strong protection against losses from credit defaults. An 'AAf' rating signal the portfolio provide protection against losses from credit defaults while an 'Af' means adequate protection against losses from credit defaults.