For the second straight quarter, Hewlett-Packard beat out Dell as the No. 1 vendor of PCs in the world, according to research firms IDC and Gartner.

In the fourth quarter of 2006, HP shipped more than 11 million PC units worldwide, while Dell shipped about 9.5 million, according to the two reports that were released Jan. 16. In the third quarter of 2006, IDC and Gartner both said HP had beat out Dell, thus claiming the top spot for the first time since 2003.

For the entire year, HP and Dell appeared tied for the top spot among PC vendors. According to the IDC study, HP and Dell were each responsible for 17 percent of the total number of PCs shipped worldwide, while according to Gartner, the two PC giants were tied at 15.9 percent each. All the results from IDC and Gartner were considered preliminary.

Overall, the PC market grew during the fourth quarter, although not as much as expected. Gartner research found that the market grew 7.4 percent, while IDC found that the market grew 8.7 percent, which was 1.4 percent below the firm’s expectations.

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In a statement, Gartner analyst Mikako Kitagawa wrote that PC makers faced competition for dollars from consumer goods, such as game consoles and televisions. Some of the uncertainty around the launch of Microsoft’s Windows Vista operating system, Kitagawa said, also slowed growth.

“In the consumer market, the PC industry battled for wallet share against other consumer electronics products, such as games consoles and flat-panel TVs, while at the same time cutting prices to ensure [that] market demand did not stall prior to Microsoft’s Vista consumer launch in January,” Kitagawa wrote.

In terms of worldwide PC shipments in the fourth quarter of 2006, HP held 17.4 percent of the market, with the company’s shipments up 23.9 percent compared with the fourth quarter of 2005. Overall, the Palo Alto, Calif., company shipped more than 11.6 million PCs.

Dell, on the other hand, held 13.9 percent of the worldwide market in the fourth quarter, a decrease of 8.7 percent compared with the same time in 2005. The Round Rock, Texas, company shipped almost 9.4 million PCs during the fourth quarter.

Dell continued to struggle with its image this quarter. Despite solid third-quarter financial results released on Nov. 11, the company was forced to delay its report due to ongoing problems with a U.S. Securities and Exchange investigation.

Dell has tried to reinvigorate itself with its Dell 2.0 plan, which launched in September. So far, the program has yet to show results.

“Dell’s market share was its lowest in four years,” Kitagawa said in the statement. “It lost market share across all segments in the [United States], particularly the home market. The fourth quarter’s consumer bias favors HP; however Dell’s accelerated shipment decline in the fourth quarter is surprising.”

HP has its own legal and ethical issues in 2006, but those issues do not seem to have affected the company’s performance.

In terms of worldwide sales, the rest of the top five consisted of Lenovo with 7.l percent of the market, Acer with 6.8 percent and Toshiba with 2.8 percent, according to Gartner.

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For sales within the United States, the news was slightly better for Dell, which claimed 29.1 percent of PCs shipped in the fourth quarter. HP was second with 25.3 percent of the market, according to Gartner. Overall, Dell shipped about 600,000 more PCs in the United States than HP.

Gateway was third with 7.1 percent of the U.S. market, while Toshiba held the fourth spot with 5.3 percent. Apple, which was fifth, only accounted for 5.1 percent of the total number of PCs shipped in the United States, but the company watched its market share grow by 30 percent compared with 2005.

In the IDC report of worldwide sales, HP held the top spot in the fourth quarter with 18.1 percent, while Dell was second with 14.7 percent. HP watched its total shipments grow 23.8 percent compared to 2005 but Dell’s fell 8.4 percent.

The other top PC vendors in terms of worldwide sales included Lenovo, Acer and Toshiba.

In the United States, Dell held the top slot with 27.9 percent of overall shipments in the fourth quarter, but the company’s shipments fell 16.7 percent compared with 2005. HP was second with 24 percent of the market and its shipments increased by 15.9 percent, according to IDC.

Gateway, Apple and Toshiba rounded out the top five in IDC report. Once again, Apple showed the greatest year-over-year growth with a 31.8 percent increase.

In terms of worldwide sales for all of 2006, Gartner’s preliminary analysis found HP and Dell tied with 15.9 percent of the market. Lenovo was third with 7 percent, while Acer was fourth with 5.8 percent and Toshiba was fifth with 3.9 percent.

IDC’s preliminary analysis gave similar results, with Dell and HP tied with 17 percent. Lenovo was third with 7.3 percent of the market, Acer was fourth with 5.9 percent and Toshiba was fifth with 4 percent.

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