Research group Gartner Inc on Monday raised its 2009 forecast for personal computer shipments, citing stronger-than-expected third-quarter sales.

The industry tracker said it now expects 2009 shipments to rise 2.8 percent to 299 million units. It had previously forecast a 2-percent decline.

Gartner's new outlook was the latest piece of good news for the PC industry, which is beginning to rebound from lows seen earlier in the year, helped by sales of inexpensive consumer notebooks and netbooks.

But Gartner warned that PCs have seen a unprecedented decline in average selling prices (ASP) this year. As a result, the market value of PC sales in 2009 is expected to fall 10.7 percent to $217 billion.

The rapid decline in PC ASPs reflects a marked shift towards lower price points as customers have looked for 'good enough' PCs at the cheapest price, and vendors have tried to spur market growth by catering to ever-lower price points, Gartner analyst George Shiffler said in a statement.

We expect PC ASP declines to slow as the market recovers, but given the market's competitive dynamic, we don't see PC ASPs rising any time soon.

Gartner is expecting seasonally modest shipment growth in the fourth quarter of 2009. For 2010, it forecast unit growth of 12.6 percent.

(Reporting by Gabriel Madway, editing by Maureen Bavdek)