In separate reports released on Monday, Gartner and IDC both found that the Round Rock, Texas-based company had increased shipments of PCs by more than 20 percent, year-over-year. HP remained in second place to Dell, both research firms said.
"Dell completely blew its competitors away again," IDC analyst Roger Kay said.
IDC found that 44.2 million personal computers were shipped worldwide in the third quarter, a rise of 11.9 percent year-over-year. Gartner, which uses a different tracking method, said global shipments in the quarter increased by 9.7 percent to 46.9 million.
Gartner said the total number of shipments was slightly below expectations, as a result of weakness in the PC market in the United States. By contrast, IDC said shipments were about 0.5 percent more than forecast and attributed the lift to the business replacement cycle.
"I was impressed," IDC's Kay said. "The backbone of the quarter is the commercial segment."
IDC said Dell's market share in the third quarter climbed to 18.2 percent, from 16.9 percent a year earlier. Shipments jumped 20.7 percent year-over-year to 8.1 million.
HP's second place came with a dip in market share, according to IDC, which said the Palo Alto-based computing giant claimed 16.2 percent of global shipments--a decline of 0.4 percentage points, year-over-year.
But Gartner, whose report was based on preliminary estimates, said the company, which sells computers under both the HP and the Compaq brand, had held its ground amid strong challenges from competitors.
"HP is coming under pressure in the U.S. retail market as rivals compete more aggressively for shelf space," Gartner analyst Charles Smulders said in a statement.
HP remained the market leader in Europe, the Middle East and Africa and saw strong growth in Asia, according to IDC. "Nevertheless, year-on-year growth in the United States dropped to low single digits, due to a difficult comparison with the company's aggressive push in the second half of 2003 and rising competition in the consumer segment," IDC said in the report.
IBM ranked third in worldwide shipments, followed by Fujitsu/Fujitsu Siemens and Toshiba, according to IDC.
Gartner had the same top 5 rankings, with Dell increasing its lead to 16.8 percent of the worldwide market share. HP's market share remained flat year-over-year, at 15 percent, according to Gartner.
Both IDC and Gartner define PCs to include desktop machines, mobile computers (but not handheld personal digital assistants) and x86 servers.