Apple plans to launch a thinner MacBook possibly at the end of 2014 or in 2015. Production of components has begun in small volumes, according to Taiwan-based supply chain makers.

Apple sold 4.41 million Macs from April-June 2014, up 7% from the previous quarter and 18% on year. Among the sales, 80% were contributed by the MacBook product line, the sources noted.

Currently, the MacBook Air's thickness is 0.3-1.7cm, while the MacBook Pro with Retina has a thickness of 1.8cm. The 13.3-inch MacBook Pro features a thickness of 2.4cm, but the model is expected to be retired by the end of 2014.