Apple Computer again cracked the top three in U.S. PC sales for the second quarter, according to surveys released Wednesday by both Gartner and IDC.

Apple Computer again cracked the top three in U.S. PC sales for the second quarter, according to surveys released Wednesday by both Gartner and IDC.

Worldwide, Apple didn't make the top five PC vendors, according to both firms. But within the U.S., IDC estimated that Apple finished in a virtual dead heat with Acer for third place, just 2,000 units behind the Asian PC maker. Gartner, meanwhile, said that Apple took the third-place spot outright, topping Acer by 65,000 PCs sold.

Both IDC and Gartner retroactively ranked Apple fourth in sales for the second quarter of 2007, if measured against a merged Acer-Gateway business. If treated as separate companies, Apple would have maintained its third-place ranking.

Both sets of data are preliminary, the firms said. The PC sales estimates include desktops, laptops, and X86 servers, but not handheld PCs. Ultraportables and so-called mini-notes were also included, although Gartner estimated that they represented just 3 percent of the market.

Domestically, Dell maintained its top spot, capturing 31.9 percent of the market according to Gartner, with 5.25 million PCs sold; IDC said that Dell's market share was 32.0 percent, with 5.44 million PCs sold. Both firms estimated that Dell grew between 11 and 12 percent from the same quarter a year ago.

HP finished second in U.S. sales, with a 25.3 percent share according to Gartner, and a 25.1 percent share according to IDC; the firm sold 4.17 million and 4.26 million PCs, according to the respective firms. HP's year-over-year growth was sluggish, about 5.6 to 5.9 percent.

Treated as a merged company that included Gateway's results, Acer's sales slipped about 20.8 percent from year to year, finishing at 1.33 million shipments or about an 8.1 percent market share, according to Gartner.

Apple, however, showed tremendous growth: 38.1 percent year over year, Gartner said, or 31.7 percent by IDC's estimates. Apple sold 1.40 million units, according to Gartner, and 1.32 million according to IDC. In total, that gave Apple an 8.5 percent or a 7.8 percent market share, according to the respective firms.

According to Gartner, total U.S. PC shipments increased 4 percent to 16.4 million units. But the firm also said that U.S. consumers are increasingly turning to low-end machines as a way to save money.

"Home mobile PCs continue to have momentum in the U.S. market. However, ASP declines were greater here than in other segments. The retail space was a harsh pricing environment during the quarter," according to Mika Kitagawa, the Gartner analyst in charge of the report.

Worldwide, PC shipments rose 15.3 percent according to IDC, to 70.6 million units. On a global scale, the top five vendors showed excellent growth; fourth-ranked Lenovo grew the least of the group, at 14.6 percent. HP grew 16.8 percent to lead the market with 13.3 million units shipped, and a 18.9 percent market share. Dell was second, growing 21.4 percent to 11.6 million units and a 16.4 percent share. Third-ranked Acer grew 63.5 percent when Gateway's numbers were factored in, finishing with 6.97 million units and a 9.9 percent share. Lenovo sold 5.6 million units and finished with a 7.9 percent market share, while Toshiba grew 28.5 percent to 3.1 million units and a 4.4 percent share.

Editor's Note: The IDC and Gartner results were for the second quarter, not the third, as the story originally stated.