The Reserve Bank of India (RBI) on Wednesday extended the tenure of the working group to review the system of loan pricing by banks to improve transmission of monetary signals on to interest rates in the economy. The central bank said it has extended the tenure of the working group on the Benchmark Prime Lending Rate (BPLR), set up in June, to October 16 from end-September earlier. Indian banks benchmark their lending to prime lending rates, but in the last few years they have begun lending to customers at way below the prime rates. The central bank's working group reviews issues like the concept of benchmark prime lending rates, extent of lending below banks' prime rates and appropriate loan pricing system based on global best practices. The group is headed by central banks Executive Director Deepak Mohanty. It also examines the wide divergence in prime rates across banks and suggest a suitable benchmark for floating rates for retail lending, the statement said.