Hewlett-Packard Company (HP) replaced Dell Inc as the world leader in personal computer (PC) shipments during the third quarter, according to figures released by two influential research firms on Wednesday.Both Gartner and IDC pegged the overall third-quarter growth of the global PC market at just under 7%, but that trend was overshadowed by the industry's new pecking order.The change of guard occurred after HP's shipments climbed 15% from a year ago while Dell's edged up by less than 4%.By Gartner's measure, Palo Alto, California-based HP shipped 1,10,000 more PCs than Dell to give it a 16.3% share of the global market compared to 16.1% for its Round Rock, Texas-based rival Dell.IDC calculated things differently, but also agreed HP holds a narrow lead in the global market. Although HP shipped 28,000 more PCs than Dell during the quarter, IDC pegged both companies market share of the worldwide market at roughly 17%.