The days of the 13-inch MacBook could be numbered, analyst Ming-Chi Kuo of Concord Securities has said.

Kuo told Apple Insider that Apple's internal shipment forecast for the 13-inch MacBook disappears after August, meaning that it could be phased out by then.

The entry-level MacBook costs £867 in the UK and $999 in the US, the same price as the 11-inch, 64GB SSD MacBook Air. In Kuo's opinion, the entry-level MacBook Air is more than a match for the entry-level MacBook, removing the need for Apple to stock the 13-inch MacBook.

It is expected that Apple will announce new MacBook Air models in the near future - perhaps even today with the launch of Mac OS X 10.7 Lion.

Apple sold 2.79 million portable Macs during the last quarter, with the MacBook Pro and MacBook Air driving those sales, according to the company's chief financial officer Peter Oppenheimer, speaking at yesterday's financial results conference call yesterday.

But Kuo reckons that MacBook accounted for less than 10 percent of the company's total Mac shipments during the first half of 2011, with monthly shipments only around the 80,000 to 100,000 mark.

The new MacBook Air models that are rumoured to be launching before the end of the month could feature backlit keyboards, a feature present in the original MacBook Air range, but missing from the second generation.

High-speed Thunderbolt ports could feature in the new MacBook Airs, as could Intel's Sandy Bridge architecture and possibly high-speed 400MBps flash memory.