The top-four Taiwan-based notebook ODMs all saw their profits decline significantly in the second quarter of 2015, and it still remains unclear if they can turn around in the second half of the year amid slowing economic growth globally.

Wistron, a front-runner in terms of profitability, saw its net profits sink 89.4% sequentially to NT$77 million in the second quarter of 2015. The earnings translated into an EPS of NT$0.03, the lowest quarterly earnings since the third quarter of 2004.

With an EPS of NT$0.32 in the first half of 2015, it will be difficult for Wistron to post an EPS for all of the year to be higher than the NT$1.5 recorded in 2014.

While Wistron's notebook shipments are expected to grow to 4.9 million units in the third quarter from 4.6 million shipped a quarter earlier, the maker remains conservative about its shipment performance in the fourth quarter due to weak visibility.

For other vendors, Quanta Computer, Inventec and Compal Electronics saw their net profits slide 8.14%, 19.45% and 25.3%, respectively, on quarter during the April-June period.

Quanta is expected to ship 4.1 million notebooks in September - the same amount it shipped in August - and sees its third-quarter notebook shipments reach 11.4 million units, up 6.54% on quarter. But Quanta also expects its notebook shipments to drop in October.

Compal shipped 3.2 million notebooks in August, up from 2.8 million units in July and expects its September shipments to have a chance to reach four million, surpassing the 3.9 million unit mark set in June. However, the company is not yet able to provide an estimate figure for the fourth quarter due to poor visibility.

Although current inventory levels at the channels are low and notebook vendors are likely to roll out new models for the year-end holiday season, overall notebook shipments from Taiwan-based notebook ODMs in 2015 are likely to be lower than the amount shipped a year earlier.