Intel Corp reported better-than-expected quarterly earnings and revenue, boosted by improving PC demand and growth in its data center and cloud businesses, but its revenue forecast for the current quarter disappointed Wall Street.

The world's largest chipmaker's shares were down 5.3 per cent at US$35.75 in after-hours trading on Tuesday.

Intel said it expects fourth-quarter revenue of US$15.7 billion, plus or minus US$500 million. Analysts on average were expecting US$15.86 billion, according to Thomson Reuters.

"This is below the average seasonal increase for the fourth quarter as we expect the worldwide PC supply chain to reduce their inventory," Executive Vice President Stacy Smith said on a conference call with analysts.

Last month, Intel raised its third-quarter revenue forecast for the first time in more than two years, citing improving PC demand.

The company's decision to raise third-quarter forecast moved investors' expectations to a higher level, Stifel Nicolaus analyst Kevin Cassidy said.

Revenue from the data center business, which offers storage and cloud-based software services, rose 9.7 per cent to US$4.54 billion in the third quarter, from a year earlier.

Revenue growth from this unit for the full year will likely be in the high single digits, Intel Chief Executive Brian Krzanich said on the call.

Demand for cloud-based services has been growing as more businesses shift to cloud-computing methods.

Intel, which has been hurt due to weak PC demand, said last month it was seeing signs of improvement among PC parts suppliers.

According to research firm IDC, global shipments fell by a smaller-than-expected 3.9 per cent in the third quarter.

Revenue from the company's traditional PC business, which still accounts for over half of Intel's total revenue, rose 4.5 per cent to US$8.89 billion.

Excluding items, the company earned 80 cents US per share, above analysts' average estimate of 73 cents US.

The company's net revenue rose 9.1 per cent to US$15.78 billion, beating the average analyst estimate of US$15.58 billion.

Net income rose to US$3.38 billion, or 69 cents US per shares, in the third quarter ended Oct. 1, from US$3.11 billion, or 64 cents US per share, a year earlier.

Up to Tuesday's close, Intel's shares had risen 9.6 per cent this year, lagging the 22.8 per cent gain in the broader Philadelphia semiconductor index.