Apple's ( AAPL) iPhone is coming -- but at a price. Its much-anticipated music player/handheld device will ship in late June as planned, but the company's Leopard operating system, a rival to Microsoft's ( MSFT) Vista operating system upgrade, will be delayed, according to Apple. The Cupertino, Calif.,-based company has had to divert engineering resources to the iPhone and as a result will push the release of Leopard back by at least three months to October, it said in a statement. Shares of Apple were recently off $2.45, or 2.7%, to $89.74 in extended trading. During the past week, several sell-side analysts had expected a June release of Leopard to reaccelerate growth However, the iPhone is a bigger and much riskier bet for Apple at this stage. Not surprisingly, Apple sought to reassure investors about it. The iPhone has passed "several" of its required certification tests, said Apple. "However, iPhone contains the most sophisticated software ever shipped on a mobile device, and we had to borrow some key software engineering and QA quality assurance resources from our Mac OS X team," Apple explained. The company says that, although Leopard's features will be complete by early June, it cannot deliver what it considers a "quality release." However, it will show developers a near final version of Leopard at its developers' conference in early June, and give them a beta copy to take home for final testing. "We think it will be well worth the wait," said Apple. "Life often presents tradeoffs, and in this case we're sure we've made the right ones."