Apple's computer sales have risen dramatically while the iPhone is about halfway to its goal of 10 million units a year, the company said today as it posted strong second-quarter results that confounded sceptics who believed the market for digital music players may be saturated.

Apple sold 1.7 million iPhones and 10.6 million iPods during the quarter and shipped 2.3 million Mac computers, up 51% on the year before. Net profit was $1.05 billion (£530 million) in the three months to March, compared with $770 million in the same period a year earlier.

Apple said international sales made up 44% of its revenue of $7.51 billion in the quarter.

"We're delighted to report 43% revenue growth and the strongest March quarter revenue and earnings in Apple's history," said chief executive Steve Jobs. "With over $17 billion in revenue for the first half of our fiscal year, we have strong momentum to launch some terrific new products in the coming quarters."

However, the company was cautious about sales in the months ahead as the global economy slows. It was also tight-lipped about reportedly slow sales of the iPhone in the UK and the rest of Europe.

Asked about recent price cuts of the phone by retailers in the UK and on the Continent, chief operating officer Timothy Cook would only say: "Carrier partners can price the iPhone as low as they wish."

Apple would not comment on talk it may change its marketing policy for the Australian launch of the iPhone later this year by unlocking the phone for use on all networks.

It preferred to focus on the US boom. Finance chief Peter Oppenheimer said: "Our US business grew beautifully. Customers are loving the MacBook Air."

The lightweight laptop was introduced in January.