The second-generation Apple Watch is expected to enter mass production in the second quarter with Quanta Computer to be the sole manufacturer of the device, according to sources from the upstream supply chain.

Apple originally considered shifting some second-generation Apple Watch orders to Foxconn Electronics (Hon Hai Precision Industry), but decided to keep all the orders with Quanta as volumes will not be high, the sources noted.

Quanta and Foxconn both declined to comment on their orders.

Because of Apple Watch's weaker than expected shipments, Apple recently reduced the device's shipment forecast for 2016 down further from its estimate in the fourth quarter of 2015.

However, compared to other smartwatches, the Apple Watch still performed rather strongly and had an over 50% share in the smartwatch market at the end of 2015.