Home, auto and education loans from a host of banks have become costlier for existing borrowers by up to 75 basis points, after lenders hiked interest rates following the RBI's move to tighten monetary policy. While the country's second largest public sector lender, Punjab National Bank (PNB), raised its benchmark prime lending rate (BPLR) by 75 basis points to 11.75 per cent, Bank of Baroda, Corporation Bank and Oriental Bank of Commerce increased it by 50 basis points each to 12.50 per cent.In addition, Union Bank and IDBI upped their BPLR by 50 basis points each to 12.25 per cent and 13.25 per cent, respectively.However, the country's largest lender, SBI, has so far not hiked its BPLR.PNB Chairman and Managing Director K R Kamath said that the borrowers linked to BPLR will see a hike in interest rates of home, auto and education loans. He, however, said the existing borrowers have the option to switch over to the base rate, below which the banks cannot lend. Other bank officials also echoed similar views.From July, bankers moved to a new system of benchmarking their lending rates, namely the base rate, which has replaced the BPLR. The RBI, in its monetary review on July 27, raised the short-term borrowing or Reverse Repo rate by 50 basis points and lending or Repo rate by 25 basis points.