NEW YORK (CNN/Money) - Dell Inc. increased its lead in the market for personal computers over rival Hewlett-Packard in the second quarter 2004, a study said Thursday.

Dell (DELL: Research, Estimates) captured 18.2 percent of the worldwide PC market compared to 17.2 percent a year earlier.

Hewlett-Packard (HPQ: Research, Estimates) captured 15.7 percent of PC sales worldwide, unchanged from a year earlier, according to the report from tech research firm IDC.

IBM (IBM: Research, Estimates) came in third worldwide at 6.5 percent, Fujitsu/Fujitsu Siemens (SI: Research, Estimates) at 3.8 percent and Acer at 3.2 percent.

Strong demand in Europe helped keep industry-wide sales strong, with second-quarter growth in PC sales coming in at over 15 percent.

In the United States, the leaders were Dell with 32.7 percent of the market, HP with 19.2 percent, IBM with 5.6 percent and Apple (AAPL: Research, Estimates) at 3.7 percent. Gateway (GTW: Research, Estimates) was also expected to be in the top five, but couldn't report sales figures prior to releasing its second-quarter earnings statement.

Perhaps more troubling for HP is that its growth in the quarter only mirrored the industry average, at 15.4 percent, while Dell's growth rate came in at 22.5 percent.

But Dell traditionally does well in the second quarter on institutional purchases and HP's more consumer-oriented products do better in the fourth quarter, IDC director Loren Loverde said, cautioning against reading too much into the latest numbers.

"HP's being very competitive," said Loverde. "There's a chance they could challenge Dell in the fourth quarter, as they have in fourth quarters before."

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But the real growth gainer was Taiwan-based Acer. The maker of low-end desktops and notebooks posted a whopping 30.7 percent quarterly growth on the back of strong portable sales in Europe.

Loverde said Acer has grown by over 30 percent for the last three quarters and its growth rate in Europe has topped 50 percent, although the company is still having trouble cracking the U.S. market.

Loverde said strong demand in Europe, perhaps helped by the high euro, and solid commercial spending has been the driving force behind the 15 percent worldwide industry growth rate.

"In our view these results are better than forecast," he said. "It's a positive sign for the rest of the year."

The second quarter of 2004 marks the fifth consecutive quarter of double-digit growth for the PC industry.