MUMBAI, February 7: Silver prices nosedived by Rs 270 per kilo to close at Rs 8990 on the bullion market on Saturday on heavy offerings at higher levels coupled with weak overseas advices and lack of industrial buying, dealers said.Ready silver of .999 started weak and declined further to close at Rs 8990, disclosing a steep fall of Rs 270 from yesterday's level of Rs 9260. Raw silver of .916 fineness and tenderable silver also declined sharply to Rs 8865 and Rs 899 respectively from the last close of Rs 916 and Rs 9265.