In the last quarter of last year, HP boosted its year-on-year growth to nearly 24% — the fastest for the company since 2000 to take the lead in global PC shipment volume in that period, according to new data from research house IDC.

HP’s shipments in the US rebounded to almost 16% from a dip to single digits in the third quarter, while overseas shipments surged to more than 28% with a strong showing in EMEA, IDC said.

The picture wasn’t so rosy for Dell in the fourth quarter. Unlike HP, it was unable to recover from a limp third quarter. Its shipments in the US, which drive more than half of Dell’s volume, fell nearly 17% year-over-year. Overseas growth was better, falling just 1.5%, but there was notably slower growth in all regions, IDC said.

Dell’s focus on profitability over share is coming right at a time of aggressive competition from companies such as HP, Acer and Apple, and is compounded by a slow commercial market, said the IDC researchers. As a result, Dell is in the unusual circumstance of seeing volume decline sequentially from the third quarter in both the United States and worldwide.

Indeed, it was a busy quarter overall for the industry. There was the enterprise release of Microsoft Corp’s latest operating system, Vista, and the continuing trend to portable computers.

HP was able to capitalize on the situation, with a leading 18.1% market share in the fourth quarter, compared to Dell’s 14.7% and Lenovo’s 7.3%. Acer wasn’t too far behind with 7.1% with Toshiba trailing with 3.7%.

Still, Dell held onto its number one ranking for full year with a 17.1% share. It just pipped HP, which had a 17% share. Lenovo came in for the year with 7.3%, followed by Acer with 5.9% and Toshiba with 4%.

IDC said the numbers show that underlying pricing and segment trends were tough on Dell and Lenovo, as well as other big brands that didn’t make the top 5, including Gateway and Fujitsu-Siemens.

The U.S. market displayed an unseasonably weak performance, largely attributed to poor commercial demand, affecting vendors such as Dell and Lenovo, said IDC’s PC manager David Daoud, in a statement.

However, the consumer notebook market was solid, essentially benefiting vendors active in the retail sector. The channels were also relatively healthy, taking advantage of low component prices and healthy demand in the SMB segment.