SAN FRANCISCO - Chip manufacturing equipment maker Applied Materials Inc said tough economic conditions are hurting demand, adding to semiconductor worries after warnings by Novellus Systems Inc and Microchip Technology Inc.

The negative news pushed shares of chip companies broadly lower on Tuesday.

Comments from companies about weak economies in the United States and Europe as well, as slow PC sales, have hurt chip stocks already underperforming because of concerns about a slowdown in the sector.

“The concern is consumer is weak, PC is weak, automotive has been lumpy. Even the smartphone market on the margin is not as strong as it was a few months ago,” said CLSA analyst Srini Pajjuri.

Applied Materials Chief Executive Mike Splinter said investment by foundries and DRAM chipmakers remains soft, although spending on equipment to make chips for Apple Inc’s iPad 2 has been a bright spot.

“We’re seeing tablet buying power that’s going to end up to be 50 million units, and it seems to be all about iPad 2,” he said. “The number of other offerings we thought would come into this market are starting to come, but the volume success really has not happened yet.”

Late on Monday, Microchip Technology, which makes semiconductors for cars, PCs and other consumer devices, cut its sales outlook due to concerns about oversupply and slow demand. Its shares were down 12.7 percent to $32.71 in the following session.

Also late on Monday, chip gear maker Novellus said bookings from its customers would be flat to down 20 percent in the current quarter compared with the previous quarter. Its stock slumped 10.9 percent to $31.89 in Tuesday afternoon dealings.

Applied Materials maintained its expectations for revenue in the current quarter to be down 3 percent to 10 percent from the previous quarter, implying revenue of $2.57 billion to $2.77 billion.

“We see the problems in Greece; we see unemployment and slow economic growth here in the U.S., inflation in China,” Splinter told investors at a conference. “These things are weighing on the market and weighing on demand for the products of our customers.”

Many investors believe chip companies have spent too quickly on manufacturing expansion and could find themselves slashing capital expenditures next year.

Chip-equipment industry group Semi expects total chip gear spending this year to rise 12 percent to $44 billion, followed by a dip of about 1 percent next year.

Pajjuri said chip inventories at many electronics manufacturers are at high levels, suggesting a possible slowdown in orders to chipmakers.

Since the end of April, the Philadelphia Semiconductor Index has fallen 12 percent, compared with a 2 percent dip in the Dow Jones industrial average.

Foundries like leading contract chip manufacturer Taiwan Semiconductor Manufacturing Co Ltd are cautious but are pushing gear makers to reduce the time it takes to fill new orders.

“They’re taking the approach that business is soft at this point; but (they) want to be ready to move quickly and put that capacity in if it comes through from demand in a very, very short period of time,” Splinter said.