Apple says it sold 35 million iPhones in the January-to-March quarter, almost twice as many as it sold a year ago and above analyst expectations.

Apple's stock was down 2 percent at the close of regular trading, as investors believed phone companies had reined in iPhone sales. In extended trading, the stock rallied $38.34, or 6.8 percent, to $598.62.

Net income in the company's fiscal second quarter was $11.6 billion, or $12.30 per share. That was nearly double the net income of $6 billion, or $6.40 per share, a year ago.

Analysts polled by FactSet were expecting earnings of $10.07 per share for the latest quarter, Apple's fiscal second.

Revenue was $39.2 billion, up 59 percent from a year ago. Analysts were expecting $37 billion.

IPad sales came in below analyst expectations, at 11.8 million units. But that was still two and a half times as many as it sold in the same quarter a year ago. Apple launched a new iPad model in the quarter.

Mac sales were also slightly below expectations, at 4 million. That was up 7 percent from last year. Meanwhile, the overall PC market grew about 2 percent.

Windows PC makers are now hoping Windows 8 will give them a better chance at competing with Apple, both in PCs and tablets. Intel CEO Paul Otellini last week said he believes PCs and tablets will merge into one light device with a keyboard and a touch-sensitive screen.

Apple CEO Tim Cook dismissed that idea on a conference call with analysts Tuesday. Tablets and PCs work best as separate devices, playing to their own strengths, he said.

"You can converge a toaster and a refrigerator, but those things are probably not going to be pleasing to the user," he said.

IPhone sales accounted for 58 percent of Apple's revenue, more than ever. Three years ago, the figure was 27 percent.

As has been the trend the last year, Asia, and in particular China, accounted for much of the revenue growth. A quarter of Apple's sales now come from Asia, excluding Japan.

For the third fiscal quarter, ending in June, Apple is expecting earnings of $8.68 per share and revenue of $34 billion. Both figures are well below analyst expectations, but that's usually the case with Apple's forecasts. The company is famous for low-balling its forecasts.