shares slumped lower in pre-market trading following a series of sales by billionaire investor Warren Buffett's Berkshire Hathaway investment group late last week.
That followed sales of around $160 million, or 5.5 million shares, over the two-day period that ended on September 13, all of which have reduced Buffett's stake to around 11.2%. Late last month, HP lowered its full-year profit forecast by as much as 15 cents per share, to a new rate of between $3.30 and $3.35 per share, following a muted third quarter earnings report that included a near 10% decline in revenues linked to ongoing weakness in China and cautious corporate IT spending plans.