According to third quarter estimates from research firm Gartner, Lenovo (LNVGY) has edged out Hewlett-Packard (HPQ) to become the world’s largest PC vendor. Worldwide PC shipments in the third quarter declined more than 8% year-over-year to total 87.5 million units. The Chinese company is estimated to have shipped 13.7 million units in the quarter, representing a 9.8% year-over-year increase, compared to HP with shipments that declined more than 16% to 13.5 million units. In a statement to The Verge, however, the Palo Alto-based company claims Gartner’s report is less “comprehensive” due to its exclusion of workstations. HP instead points to rival research firm IDC and its estimates, which rank the company less than half a percentage point ahead of Lenovo. Worldwide PC shipments in 2012 are set to decline for the first time in over a decade as consumers embrace smartphones and tablets. IDC’s estimates follow below.