While some areas of the business software market hit a soft spot in the second quarter, worldwide PC shipments are still showing double-digit growth, market researchers IDC and Gartner say.

Driven by demand for replacement PCs from business users, a total of 42.8m PCs were shipped worldwide in the second quarter of this year, 13.3 percent more than the samer period last year, Gartner says in a statement. The growth was in line with expectations, Gartner says.

"Businesses delayed replacements during the economic downturn and are now replacing those older machines," says Charles Smulders, vice president of Gartner's Computing Platforms Worldwide group.

IDC, meanwhile, calculates PC shipment growth at 15 percent over the same period, to 39.7m units, beating its expectations. PC replacements, particularly of desktop systems, continued to be helped by aggressive prices, IDC says in a statement.

IDC and Gartner cover the market in largely the same way, although Gartner includes certain types of system that IDC excludes.

Dell retained its position as market leader both worldwide and in the USA, according to both research companies. They also agree that HP and IBM were the world's second and third largest vendors, respectively, in terms of units shipped.

The smallest of the top five PC vendors, Acer, again recorded the biggest growth. The company has been successful at selling low-cost portable computers in Europe and saw growth in desktop sales in both Europe and Asia, IDC says.

Gartner expects PC shipments for the full year to come in about 13 percent higher than in 2003. However, if the political and economic environments were to worsen, PC sales could also suffer, Smulders says.

"I think economic and political factors will have a large influence on the final outcome. Some of the economic news that we have seen over the past few months does concern me," he says.