Taiwan's purchasing managers' index for the manufacturing sector dropped 2.1 points from August to 53.9 in September, a Taipei-based think tank has said.

A PMI above 50 indicates expansion, while below reflects contraction. The expansion in September was the slowest since February 2017, according to the Chung-Hua Institution for Economic Research (CIER).

Despite it being the high season for orders in electronic components, the island's business outlook in manufacturing is not optimistic.

The CIER index that monitors the manufacturing business outlook for the next six months dipped 6.5 points to 47.6 in September, reversing a 30-month streak of expansion.

Meanwhile, economic activity in the services sector is also losing steam. The non-manufacturing index, a service sector indicator, fell 1.8 points to 50.8 in September.