UPDATE 3-KLA-Tencor sees lower revenue, uncertainty

* Adjusted EPS below estimate

* Investors looking for rebound in gear orders

* Chip companies scaled back orders due to economy

* Shares fall more than 2 pct after-hours

(Adds outlook for current quarter)

SAN FRANCISCO, Oct 25 (Reuters) - KLA-Tencor Corp posted fiscal first-quarter revenue below expectations and said current-quarter revenue would fall more as chipmakers, worried about the economy, hold off on new orders of manufacturing equipment.

The lower-than-expected outlook for the December quarter, including uncertainty about orders for new products, sent the company's shares down more than 2 percent after-hours.

With dwindling demand for PCs, Intel Corp and memory chip makers have been scaling back investment plans for new technology and manufacturing capacity, and Wall Street is trying to determine when orders for new gear will begin to pick up.

Booming sales of smartphones and tablets have fueled the chip industry in recent years. But even chipmakers focusing on those devices have been hurt by economic uncertainty.

``As the whole industry is pausing right now ... there is an assessment of how much investment is needed at what point, and there is a fair amount of digestion of existing capacity coming in,'' Chief Executive Rick Wallace told analysts on a conference call. ``So we still have a rather large range on the December bookings.''

KLA-Tencor's products help measure the effectiveness of complicated manufacturing processes and reduce defects, essential for chipmakers implementing challenging new technologies.

Research firm Gartner said this month that worldwide industry spending on chip equipment would slow in 2013 because of deteriorating economies.

Earlier on Thursday, top contract chipmaker TSMC Ltd forecast two quarters of weaker revenue but said demand for mobile devices would fuel a rebound from April.

Facing lower-than-expected demand for its PC processors, top chipmaker Intel is running its fabrication plants at less than 50 percent capacity, redirecting unused space and equipment to be used on more cutting-edge production lines still being built.

Wallace said revenue in the current quarter would be between $600 million and $660 million, less than expected by analysts.

He said bookings of new orders would be between $550 million and $750 million.

KLA-Tencor said first-quarter revenue was $721 million, compared with $796 million in the year-ago period.

Analysts were expecting first-quarter revenue of $740 million and current-quarter revenue of $738 million, according to Thomson Reuters I/B/E/S.

KLA-Tencor said quarterly net income totaled $135 million, or 80 cents a share in the September quarter, down from $192 million, or $1.13 a share, in the year-ago quarter.

Non-GAAP earnings per share were 84 cents. Analysts on average expected earnings per share of 89 cents.

The company's shares dipped 2.14 percent in extended trading after closing 0.02 percent higher at $47.14 on the Nasdaq.

(Reporting by Noel Randewich; editing by Gary Hill, Phil Berlowitz Dan Grebler and Matthew Lewis)