SAN FRANCISCO, March 25 (Reuters) - Market researcher Gartner Inc on Tuesday cut its forecast for worldwide personal-computer sales growth, citing the weakening economy, and cautioned that growth could fall into the single digits.

The industry is expected to ship 10.9 percent more computers this year than in 2007, Gartner said, down from an earlier forecast of 11.6 percent. In 2007, shipments grew 13.4 percent to 271.2 million units, U.S.-based Gartner estimated in January.

"The consensus among economists is we have a recession," Gartner research director George Shiffler said by phone. "It's not a question of whether there is (a recession), but how deep it's going to be and how long it's going to last."

In addition to a U.S. recession, the possibility of a sharp slowdown in China's economy following this year's Olympic games in Beijing and higher oil prices could hurt PC sales, Gartner said.

The world's top PC makers include Hewlett-Packard Co (HPQ.N: Quote, Profile, Research), Dell Inc (DELL.O: Quote, Profile, Research), Taiwan's Acer Inc (2353.TW: Quote, Profile, Research) and China's Lenovo Group Ltd (0992.HK: Quote, Profile, Research).

Shiffler said U.S. businesses may delay desktop PC replacements until next year as technology budgets tighten. Companies may decide to keep running older versions of Microsoft Corp's (MSFT.O: Quote, Profile, Research) Windows operating system before upgrading to Windows Vista, which in most cases requires a higher-performing PC to function fully, he said.

"If you have a bunch of stuff coming due for replacement this year, you could extend life cycles into next year and save yourself some out-of-pocket money," Shiffler said.

The last major desktop PC replacement cycle was from 2004 to 2005, Gartner said. It expects another, "albeit substantially more modest" replacement cycle, from late 2008 to early 2010.

Still, Gartner said the PC market "is fundamentally in good shape," with strong sales of laptop computers being spurred by falling prices and growing demand for computers in emerging markets. (Reporting by Philipp Gollner; Editing by Gary Hill)

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