Qualstar ( QBAK) said its third-quarter profits fell due to weakness in the data storage industry, and the company expects to miss fourth-quarter estimates as well. The manufacturer of automated cartridge tape libraries posted third-quarter net income of $695,000, or 5 cents a share, down from $1.3 million, or 11 cents a share, a year ago. Sequentially, the company's profits fell by almost 50%. Analysts polled by Thomson Financial/First Call had been expecting to see 10 cents a share. Revenue for the quarter was down 23% to $8.6 million from $11.1 million a year ago, missing analyst estimates of $11.50 million. In a press release, the company said its lower results were caused by weakness in the data storage industry and the technology sector overall "that has continued for a number of months." Going forward, Qualstar said that, due to limited visibility, it can only provide guidance for the fourth quarter. The company expects revenue and earnings per share to be flat to slightly up from the current quarter's results, a forecast well below the current consensus estimate of EPS of 12 cents a share on revenue of $12.14 million. Shares of Qualstar lost nearly a quarter of their value in after hours trading Monday on the news after closing at $6.75 in regular session trading.