The new base rate will be applicable from October 5.
"Almost 80 per cent of our advances are linked to base rate so there would be an impact of 20-25 basis points on our margins," the bank's Executive Director R K Takkar said.
However, the lender is planning to reduce its deposit rate at a later stage which will help in offsetting loss in margins, he added.
Earlier in the day, private lender Kotak Mahindra Bank slashed its base rate by 0.25 per cent to 9.50 per cent, effective October 5.
SBI, Andhra Bank and Bank of India were among the first to cut base rate in the range of 0.20-0.40 per cent in response to RBI's surprise action.