At OMC's chrome ore auction yesterday, 23,500 t out of the 33,500 t offered were sold, while the entire 10,000 t lot of sub-40% grade remained unsold.. Bids increased by 1-11% (INR 192-2,883) compared with last month's auction, surging 9-64% (INR 1,800-15,200) above the base price. The rise in prices is likely due to limited domestic supply and an increase in ferro chrome prices m-o-m.