Dell managed to remain the top seller of PCs last year, but No. 2 Hewlett-Packard closed the gap and captured the top ranking in the second half of the year, a market research firm says.

HP in the fourth quarter shipped 11.6 million PCs, soaring more than 21 % over the same period a year ago, iSuppli Corp. said Tuesday. The computer maker's growth rate was more than three times the industry average for the period, and kept HP in the No. 1 spot for two quarters in a row in the second half of the year.

On the other hand, Dell, which is undergoing a major reorganization as the result of an ongoing sales slump, shipped only 9.6 million PCs in the quarter, down 8.6 % from a year ago. Dell was the only top five PC maker to report a decline in fourth quarter shipments -- both sequentially and year over year.

"HP's resurgence was the most remarkable event in the PC industry in 2006," iSuppli analyst Matthew Wilkins said in a statement. "The company clearly has momentum on its side."

As Dell adjusts to recent senior management changes and the return of founder Michael Dell as chief executive, HP is expected to continue to make gains, Wilkins said.

China's Lenovo held onto third place in the fourth quarter, increasing shipments by 8.2 % year over year to 4.8 million units. Lenovo's lead over fourth-place Acer, however, shrank in the fourth quarter, as the latter company came on strong with a 42.7 % jump in shipments year over year.

Toshiba was the fifth largest PC maker in terms of shipments. The company shipped 2.45 million units, an increase of 21.3 % over a year ago.

Dell remained the No. 1 PC seller for the year, increasing shipments 4.4% over 2005 to more than 39 million units. HP, however, nearly overtook Dell, finishing the year with a 16% share to Dell's 16.3%. HP shipped 38.2 million units, 19% more than 2005.

Rounding out the top five were Lenovo, which had a 7% share; Acer, 5.5%; and Fujitsu/Fujitsu-Siemens, 3.5%. Acer narrowed the gap with Lenovo, almost doubling the latter company's growth for the year.

Total shipments for the year were 238.7 million, an increase of 8.9% over 2005.