The release of the Apple Watch will help accelerate the growth of the wearable market, pushing global shipments of wearable devices to 45-50 million units in 2015, up 125-150% from 20 million units shipped a year earlier, according to sources at Taiwan's supply chain.

Apple, which began delivering Apple Watch in April, is likely to outperform Fitbit to become the number one vendor in the segment in the second quarter, commented the sources.

Fitbit ranked as the top vendor of wearble products globally in the first quarter of 2015, with wearable shipments totaling 3.9 million units and taking a 34.2% market share, according to data compiled by IDC.

Global shipments of wearable devices totaled 11.4 million units in the first quarter of 2015, a 200% increase from the 3.8 million wearables shipped a year earlier, the data showed.