An estimated four million MacBooks will be shipped in the third quarter of 2013, increasing over 10% on quarter, but significantly decreasing from previous years, according to Taiwan-based supply chain makers.

　　Quarterly MacBook shipments usually peak in the third quarter due to the year-end sales peak, with third-quarter shipments averaging 5-6 million units in past years, the sources indicated.

　　Apple revised the MacBook Pro in 2012 and then increased 13-inch MacBook Pro orders in anticipation of good sales, the sources noted. But actual sales of the 13-inch MacBook Pro fell far short of expectations, and therefore Apple cleared inventories and suspended orders in the first half of 2013, the sources said.

　　Apple has taken stricter control of its supply chain, including introducing new suppliers, to put pressure on existing ones, the sources indicated. In addition, order visibility has become shorter than in the past, the sources noted.