Qualcomm Inc. reported quarterly earnings and revenue that blew past Wall Street expectations as demand increased for chips in devices such as smartphones and tablet computers, sending its shares up 8 percent in aftermarket trading Wednesday.

The leading supplier of chips for cellphones also gave a bullish forecast for the current quarter and the year ahead, in stark contrast with bleak outlooks from other chip companies.

San Diego, California-based Qualcomm forecast first quarter revenue of $5.6 billion to $6.1 billion compared with Wall Street expectations for $5.6 billion according to Thomson Reuters I/B/E/S. It forecast full-year 2013 revenue growth in a range of 20 percent to 26 percent from 2012.

The company's fourth-quarter sales were helped by the launch of the latest Apple Inc iPhone and other smartphones from Samsung Electronics Co.

"Clearly Apple is playing a part here, as is Samsung," said Charter Equity Research analyst Ed Snyder.

But he noted that the company was also helped this quarter by pent-up demand for its most advanced wireless chips as its revenue was stunted earlier this year by a shortage of 28 nanometer manufacturing capacity.

"The question is if it's a one-time shipment thing. How much of this was catch-up?" Snyder said.

Qualcomm's revenue rose 18 percent to $4.87 billion from $4.12 billion in the year-ago quarter and compared with Wall Street expectations for $4.66 billion according to Thomson Reuters I/B/E/S.

Qualcomm said profit for its fiscal fourth-quarter ended Sept. 30 rose to $1.27 billion, or 73 cents per share, from $1.06 billion, or 62 cents per share, in the year-ago quarter.

Excluding unusual items, Qualcomm earned 89 cents a share compared with Wall Street expectations for 82 cents according to Thomson Reuters I/B/E/S.

Qualcomm estimated first quarter earnings of 90 to 98 cents a share.

Shares of Qualcomm rose $4.64 to $62.86 after closing down almost 4 percent at $58.12 in regular Nasdaq trade.