KOLKATA: Five regional rural banks (RRBs) sponsored by United Bank of India (UBI) were amalgamated on Thursday to form Bangiya Gramin Vikash Bank (BGVB) with a total business of Rs. 4,130 crore and a credit-deposit ratio of 44 per cent. The bank would be headquartered in Berhampore in Murshidabad district and would now be in a position to reduce operational cost by rationalising manpower, says a release from United Bank.