(Telecompaper) China's Tsinghua Unigroup has sent a letter to Micron Technology outlining a bid of USD 21 per share, a total of USD 23 billion, for the US chipmaker, the Wall Street Journal reported, citing sources familiar with the matter. The potential bid price is 19.3 percent higher than the share's USD 17.61 closing price on 13 July. A Micron spokesman said the company, based in Boise, Idaho, has not received a buyout offer and declined further comment.