IBM has reportedly put its <A HREF="http://story.news.yahoo.com/news?tmpl=story&cid=530&ncid=530&e=4&u=/ap/20041203/ap_on_hi_te/ibm_pc_business">personal computer business up for sale</A> in a deal that could fetch as much as $2 billion and close an era for an industry pioneer that long ago shifted its focus to more lucrative segments of the computer business. Its stock rose 1.6 percent in early trading in the wake of the report. The New York Times said in its Friday editions that IBM is in serious discussions with the Lenovo Group, China's biggest maker of personal computers, and at least one other unidentified buyer for the unit.