As of 0153 GMT, the main TAIEX index fell 16.33 points to 8646.81, after closing up 1.77 percent on Tuesday.
The electronics subindex was up 0.1 percent. The semiconductor subindex was down 0.1 percent and the financial subindex was up 0.1 percent.
Taiwan's economic outlook remains rosy. The island's export orders for September hit a record monthly high, data issued Monday after the market closed showed, propelled by robust demand for the two new models of Apple Inc's iPhone 6.
Taiwan's export-oriented technology companies make many of the components for global smartphones.