Apple, the maker of Macintosh computers and iPod personal music players, on Thursday announced that it would delay shipment of its new “Leopard” operating system until October.

The company had originally planned to ship the latest version of its OS X operating system in June. But it said it had been forced to push back that date in order to make final preparations for the launch of the iPhone, Apple’s long-awaited mobile handset, which is also scheduled to launch in June.

“iPhone contains the most sophisticated software ever shipped on a mobile device, and finishing it on time has not come without a price,” Apple said in a statement. “We had to borrow some key [resources] from our Mac OS X team, and as a result we will not be able to release Leopard…in early June as planned.”

“Life often often presents trade-offs, and in this case we’re sure we’ve made the right ones,” the company added.

Shares of Apple fell 2.7 per cent in after-hours trading following news of the delay. The shares had risen from a low of $50.67 in July last year following several strong quarters of iPod sales.

The shares have continued on their upward path since January on hopes that the company’s long-awaited foray into mobile handsets will provide it with a significant sales boost.

Apple’s decision to push ahead with the iPhone at the expense of its new operating system reflects a realignment of priorities at the company.

Steve Jobs, Apple’s co-founder and chief executive, earlier this year changed the company’s name from Apple Computer to Apple in recognition of its move away from its core computer business into consumer electronics and digital media devices.

Apple said on Thursday that the iPhone had already passed several certification tests.

It said it would make a “near-final version” of the Leopard operating system available to developers attending its annual developers conference in June, with a competed version to follow in October.