NEW DELHI — India's central bank has cut its key interest by a quarter of a percentage point to 5.15%, a fifth consecutive reduction, and has also lowered its economic growth forecast for the 2019-2020 financial year to 6.1% from 6.9% projected earlier.

The Reserve Bank of India in a bimonthly review of the economy on Friday said the reduction is necessary to revive growth from a six-year low.

The benchmark interest rate is what the bank charges on lending to commercial banks.

India’s first quarter GDP growth plunged to 5% with consumer spending and corporate investment faltering. Declining industrial output and automobile sales also raised fears of a deeper slowdown.

The bank said Friday that abundant rains in August and September have brightened the prospects of agriculture and revival of domestic demand.