Separately, the Financial Times reported on Friday that Apple was being pressured by big music companies to change its business model for iTunes.

Record labels including Universal, EMI and Warner want Apple to offer a subscription service and allow for variable pricing for different tracks. At present Apple sells tracks at 99c per song and has announced plans to sell a version of EMI songs for 30c more, without copy protection known as digital rights management (DRM).

Apple stock fell 3.2% in late trading after Apple said Leopard, an update to its Mac operating system, will be pushed back to October instead of June.

he iPhone handset will ship in late June in the US, Apple said in a statement today.

"IPhone contains the most sophisticated software ever shipped on a mobile device, and finishing it on time has not come without a price, " the California-based company said. "Life often presents trade-offs and in this case we're sure we've made the right ones."

CEO Steve Jobs in January unveiled the iPhone, which combines the best-selling iPod music and video player with an internet-connected mobile phone. Apple developed new software to handle the device's touch screen. Jobs expects to sell 10m iPhones in 2008, capturing 1% of the mobile-phone market.

"They had to make a choice and one of them was going to slip, " said Jonathan Hoopes at ThinkEquity Partners in New York. He has a 'buy' rating on the shares and doesn't own any. "They made the right choice."

Shares of Apple fell as much as $2.94 to $89.25 in extended trading. The stock has gained 8.7% this year.

With the iPhone, Jobs is working to extend Apple's dominance in the digital media market into the larger mobile-phone arena, which is expected to reach 1bn devices next year. The company said this month that it has sold 100m iPods in the 5 1/2 years since Jobs unveiled the device.

That's made it the best-selling media player in the US.

Apple plans to release two versions of the iPhone, a $499 model with 4 gigabytes of memory and a $599 8-gigabyte model. The devices will be released in Europe later this year and in Asia next year, the company said.

The company may sell 850,000 iPhones this fiscal year, which ends in September, UBS analyst Benjamin Reitzes said in a report. He rates the shares 'buy' and doesn't own them.

Apple promised today to deliver "a near final version" of Leopard at its developers' conference 11 June in San Francisco. Attendees will be able to take home a test 'beta' version of the software, company spokesman Steve Dowling said.

"The features will be complete in the beta version, " Dowling said.

Sales of Leopard may reach $50m to $75m a quarter and add up to 5 cents a share to earnings, Citigroup analyst Richard Gardner said in an April report. Gardner, based in San Francisco, has a 'buy' rating on the shares and doesn't own them.