SANTA CLARA, CA — Surging iPad shipments have propelled Apple to a 17.2% share of worldwide mobile PC shipments in the fourth quarter, pushing the company to the top of the market share rankings.

According to preliminary results from the DisplaySearch Quarterly Mobile PC Shipment and Forecast Report, Apple shipped more than 10.2 million notebook and tablet PCs combined, nearly a million more units than HP in the fourth quarter. While Apple’s iPad is benefiting from a first-mover advantage, particularly in mature markets, its notebook PC shipment growth rate continues to exceed the industry average.

“While we anticipate increased competition in the tablet PC market later this year with the introduction of Android Honeycomb-based tablets, Apple’s iPad business is complementing a notebook line whose shipments widely exceed the industry average growth rate,” said Richard Shim, senior analyst at DisplaySearch. “Apple is currently benefiting from significant and comprehensive growth from both sectors of the mobile PC spectrum, notebooks and tablet PCs. Cannibalization seems limited at this point.”

Among the top five brands in the mobile PC market, Toshiba was the only other company to exhibit year-over-year shipment growth. Toshiba’s shipments increased 15% year-over-year, to over 5.1 million units in the quarter, as it maintained its #5 position in market share. HP, Acer Group (including Founder shipments), and Dell took the no. 2, 3, and 4 positions, respectively. The top five brands accounted for 65.4% of the total mobile PC market.

In the quarter, worldwide mobile PC shipments (including tablet PCs) reached 59.6 million, up 8% sequentially and 17% year-over-year, the highest volume since DisplaySearch began to track this segment, in 1999. Growth of notebook PC shipments, excluding tablets, was weak, up 4% sequentially and 1% year-over-year.

Preliminary Q4’10 Worldwide Top Five Mobile PC Shipment Rankings by Brand (millions)

Source: DisplaySearch Quarterly Mobile PC Shipment and Forecast Report–Preliminary
* Includes Founder shipments