A number of stocks related to PCs are sliding after research firm CSLA warned that PC sales in emerging markets are slowing more than it had previously expected. In a note to investors this morning, CLSA analyst Nicolas Baratte reported that sales of computer notebooks and netbooks in emerging markets dropped 1% in the third quarter compared with the same period in 2011. Sales of PCs to emerging market companies sank 7%, and worldwide sales of desktops tumbled 10% in the third quarter, the analyst added. Furthermore, the analyst expects PC sales in developed markets to decline by 9% in 2012 and continue dropping in coming years. On a positive note, Baratte expects PC sales in emerging markets to begin growing again during the current quarter, before jumping 9% in 2013. The analyst continues to have a cautious view of Hewlett Packard (HPQ), Dell (DELL), Seagate Technology (STX), and Western Digital (WDC), and he added that Dell and Hewlett Packard seem to be unable to recover from sizable share losses in the PC market. Baratte maintains Underperform ratings on Seagate, Western Digital, and Hewlett-Packard, and an Outperform rating on Dell. Meanwhile, a decision by Seagate CFO Patrick O'Malley to sell 57,280 shares of the company's stock may also be weighing on Seagate in particular and the sector in general. O'Malley sold the shares on November 21, but the transaction was revealed in an SEC filing last night. In early afternoon trading, Seagate fell 4.59% to $26.09, Western Digital gave back 2.67% to $34.85, Dell slid 1.61% to $9.78, and Hewlett-Packard dropped 1.65% to $12.53.