Apple has placed orders for new MacBook Pro models unveiled in October in large volumes due to expected good sales in the fourth quarter. The orders have filled up some of its suppliers' capacities, according to Taiwan-based supply chain makers.

　　However, most of the suppliers are unwilling to expand capacities on concerns that Apple may stop taking its ordered shipments suddenly like it did in the fourth quarter of 2012.

　　Apple reported Mac series shipments of 4.57 million units in its fiscal fourth quarter of 2013, up 21% sequentially. Market watchers estimate that the growth was mainly contributed by its MacBook Air and iMac, which recently received specification upgrades.