UPDATE 1-Gartner lowers second-half PC sales forecast

* US, Europe economic woes threaten PC sales revival

* Could have effect on Intel, Microsoft (Adds first-half sales, Gartner comment)

SAN FRANCISCO Aug 31 (Reuters) - Technology research firm Gartner cut its forecast for personal computer sales for the second half of the year by 2 percent, signaling that a resurgence in tech spending that started earlier this year may not be as strong as expected.

Worldwide PC shipments are now projected to grow by just over 15 percent for July through December, said Gartner. That's slightly lower than its previous forecast, largely due to the return of economic uncertainty in the United States and Western Europe. First-half PC sales grew 24 percent.

"There is no doubt that consumer, if not business, PC demand has slowed relative to expectations in mature markets," said Gartner research director Ranjit Atwal. "The PC market revived in the first half of 2010, but the real test of its resilience is yet to come."

Slower-than-expected growth in PC sales is bad news for chipmakers such as Intel Corp (INTC.O) and software maker Microsoft Corp (MSFT.O). Last week Intel warned that third-quarter revenue could fall short of its own estimates by more than $1 billion, reinforcing doubts about the strength of a technology sector recovery. [ID:nN27260125]

Overall this year, Gartner expects a 19.2 percent increase in worldwide PC sales to 367.8 million units, helped chiefly by higher growth in spending by consumers rather than businesses.

"Consumer demand is likely to remain strong even if the economic recovery stalls because consumers now view the PC as a relative 'necessity' rather than a 'luxury' and will continue to spend on PCs, even at the expense of other consumer electronic devices," Atwal said. (Reporting by Bill Rigby, editing by Gerald E. McCormick)