* Growth 10.5 pct vs forecast 13.5 pct
* HP shipments flat, loses share
* Acer, Dell grow slower than market; Apple surges
SAN FRANCISCO, Oct 13 (Reuters) - Worldwide sales of personal computers rose a less-than-expected 10.5 percent in the third-quarter, industry tracker IDC said on Wednesday, hampered by weak consumer spending in the United States.
Global PC shipments totaled 89.3 million units in the July-September period, with the U.S. experiencing 3.8 percent growth versus IDC's expectation of near 11 percent.
"Despite a sluggish start, the quarter ended with a good rally in September which could be a good prelude for what is ahead," said IDC analyst Jay Chou in a statement.
Top PC maker Hewlett-Packard (HPQ.N) turned in the weakest performance of the major vendors. Shipments were essentially flat from a year ago, and the company lost nearly two percentage points of market share, falling to 17.7 percent.
Second-place Acer Inc (2353.TW) and third-place Dell Inc DELL.O both posted growth that was lower than the overall market. Acer's market share slipped to 13 percent, while Dell's was nearly flat at 12.5 percent.
Lenovo Group Ltd (0992.HK) and Asustek Computer Inc (2357.TW) both posted robust growth above 30 percent, while Toshiba grew at a roughly 15 percent rate.
Apple Inc (AAPL.O) does not rank among the top six PC makers globally, but the company turned in a strong performance nonetheless. Apple PC units grew 24 percent in the third-quarter in the U.S., where it ascended to the No. 3 ranking. (Reporting by Gabriel Madway; Editing by Bernard Orr)