As far as its design is concerned, the Apple MacBook Air line has remained the same for several years now. Nevertheless, there are rumors that a new MacBook Air is in the works and, citing sources, the Wall Street Journal has claimed that Apple suppliers have already started mass production of a new 12-inch MacBook Air.

Latin Post reports that the dominant feature of the new MacBook Air is includes a higher resolution display, or the Retina display. However, the upcoming laptop will not come with full-sized USB ports, SD Card slot or even the MagSafe connector.

Sources claimed that Apple's suppliers intend to begin shipping the upcoming device in "large quantities in the second quarter," but they failed to reveal the exact launch date of the 12-inch MacBook Air.

Currently, the MacBook Air is available with an 11-inch screen display rendering a resolution of 1,366 x 768, in addition to a 13-inch model with a resolution of 1,440 x 900.

Apart from the above mentioned models, Apple already offers a more expensive MacBook Pro with a retina display. The 13-inch device has a resolution of 2,560 x 1,600 pixels, while the 15-inch version comes with a resolution of 2,880 x 1,800 pixels.

The report quotes the Cupertino-based tech titan claiming that compared to the standard display, Retina display offers fourfold the number of pixels, a wider viewing angle, unbelievable detail, higher contrast, richer blacks as well as reduced glare. Apple has ensured that the latest versions of Mac OS X have applications that sustain the higher resolution.

It is believed that Apple has decided to offer Retina display with a view to keep up with its rivals. Meanwhile, even vendors have not only started upgrading their Windows PC ultrabooks with high-resolution displays, but are offering them at retail prices that are much lower compared to the Air.

Usually, Apple offers two screen sizes on any of its products and if the company does launch the purported 12-inch Air, it may drop either the 11-inch or the 13-inch model eventually.