Intel Corp posted a 43 percent rise in quarterly profit on Tuesday and raised its revenue forecast to above Wall Street expectations, sending its shares up 4 percent.

Intel said its third-quarter net income rose to $1.86 billion, or 31 cents per share, from $1.30 billion, or 22 cents per share a year earlier. Results were helped by higher sales of microprocessors for notebook computers and Intel's restructuring efforts.

The company, which is making gains against its smaller rival, Advanced Micro Devices Inc, also said revenue in the third quarter rose 15 percent to $10.1 billion.

I think people were expecting more cautious comments about the fourth quarter, said CRT Capital Group analyst Ashok Kumar. They are benefiting from mis-execution on AMD's part and it's likely they'll continue to gain market share.

For the current quarter, Intel forecast revenue of $10.5 billion to $11.1 billion and a gross margin of 57 percent, plus or minus a couple of percentage points.

Analysts had expected Intel to post fourth-quarter revenue of $10.4 billion, according to Reuters Estimates.

Shares of Intel, based in Santa Clara, California, rose to $26.59 in after hours trading compared with their Nasdaq close of $25.48.

The stock has been trading at more than 18 times expected 2008 earnings. Before the latest results, Intel shares were up nearly 30 percent this year, while those of smaller rival Advanced Micro Devices Inc have dropped about 30 percent.

(Reporting by Duncan Martell)