Apple has a new iPhone, two new iPads and three new PCs as it heads into the Christmas quarter, the biggest selling season of the year.

But, paradoxically, it expects these new gadgets to bring down its profits compared to last year.

The reason is that the new gadgets are expensive to make, Apple executives said last night.

They added that the company is not interested in cutting corners for the sake of short-term returns.

On top of the warning, Apple posted earnings for its just-ended quarter that missed Wall Street's expectations for the second quarter in a row.

This has not happened in more than a decade.

The issues facing Apple are a normal consequence of having so many new products, its chief financial officer Peter Oppenheimer said last night.

When a production line is new, it costs more to run and the components are more expensive. "The difference this time is the sheer number of products we're introducing at a short time''.

But Oppenheimer also singled out the iPad Mini, the new, smaller version of the iPad the company unveiled earlier this week. It starts at $329, well above the $199 competitors charge for similar products. Apple's price is "aggressive," with a margin well below its other products, Oppenheimer said.

"When we set out to build the iPad Mini, we didn't set out to build a small, cheap tablet, we set out to build a smaller iPad that offered the full iPad experience" Oppenheimer said.

Apple expects a gross profit margin of 36% in the current quarter, the lowest figure in at least four years. Its gross margin was 44.7% the same time last year. The gross margin represents what Apple gets from selling its products, minus the cost of making them. It ignores the cost of research and development, marketing and corporate overhead.

Apple's chief executive Tim Cook also justified the projected profit drop to Wall Street in similar terms.

"We're unwilling to cut corners in delivering the best product experience in the world," he said. "We're managing the company for the long run."

Apple launched the iPhone 5 a month ago. This week, it unveiled the iPad Mini and an upgraded full-size iPad, plus a new MacBook laptop and two desktop Macs. Apple said it expects earnings of $11.75 a share in the next quarter, below the $13.87 a share it earned the same time last year.

Apple routinely dampens its estimates, but this time the forecast was further from the analyst estimate than usual. Analysts were expecting earnings of $15.59, on average.