Apple powered ahead in its fiscal fourth quarter driven by iPhone demand, not least that of the new iPhone 6 and 6 Plus, but demand for its iPad tablet was a weak spot.

The company posted revenue of $42.1 billion for the quarter ended 27 September, a 12.3 per cent increase over the year ago period, and net profit of $8.5 billion, a jump of 13.3 per cent.

The three-month period benefited from just over a week of the iPhone 6 and 6 Plus sales, launched on 19 September. Total iPhone unit sales were 39.3 million, up 16 per cent from a year ago.

“Our fiscal 2014 was one for the record books, including the biggest iPhone launch ever with iPhone 6 and iPhone 6 Plus,” said CEO Tim Cook.

Less stellar was the performance of the iPad. Apple sold 12.3 million tablets in the fourth quarter, a figure down 13 per cent from the year-ago period. This is the third quarter in a row that iPad volumes have fallen.

Elsewhere, Apple said revenue from the App Store grew by 36 per cent in the quarter from a year ago, and cumulative app downloads have passed 85 billion.

Looking forward, Apple forecast revenue of $63.5 billion to $66.5 billion for the final quarter of 2014, which would represent an increase of about ten per cent from the year ago period. This figure would exceed analyst estimates of approximately $63.5 billion.

The company also talked up the future prospects from the launch of its enterprise partnership with IBM, which will launch its first jointly-developed apps next month. These apps will target six industry sectors.

CFO Luca Maestri told Reuters the partners had signed up 50 initial clients for their joint initiative.