STAMFORD, Conn. (AP) -- A rebound in purchases of personal computers worldwide will lead to a 2.8 percent increase in shipments this year, driven by sales of netbooks, according to a technology research firm.

Gartner Inc. sees worldwide PC shipments topping 298.9 million in 2009, a reversal from its prior forecast of a 2 percent decline, after consumers snapped up a larger-than-expected number of computers in the third quarter.

PC shipments fell in the first half of this year as consumers and businesses remained in the grip of the recession. But many PC makers have reported improved third-quarter sales.

Gartner sees an even more bullish showing in PC shipments for 2010, up 12.6 percent to 336.6 million.

But the value of computer sales is expected to drop by 10.7 percent to $217 billion this year because manufacturers are cutting prices to move product. Next year will be slightly better, up 2.6 percent.

"Blame this year's drop in market value on the unprecedented declines in PC average selling prices we've seen this year," said George Shiffler, Gartner's research director, in a statement.

Consumers eschewed top-of-the-line PCs to ones that were "good enough" at the cheapest price and retailers have responded by lowering their prices, he said.

The rate of price drops should slow, but Shiffler doesn't see prices rising any time soon because of stiff market competition.

"As a result, growth in the market value of shipments will significantly lag shipment growth next year and beyond," Shiffler said.

Mobile PCs, including netbooks, are expected to see a 15.4 percent increase in shipments to 162 million this year and up 21 percent in 2010. Gartner sees 29 million netbooks shipped this year and rising 41 percent to 41 million next year.

Gartner said Microsoft Corp.'s newest operating system release, Windows 7, is not expected to drive computer sales. Rather, consumers will buy PCs based on the deal they get on the computer. As for companies replacing their computers due to the Windows 7 release, Gartner doesn't expect any changes to take place until the latter part of 2010.