The iPhone 4S. (Photo/Cheng Kuang-hung)

Handset shipments to Taiwan fell sharply in the second quarter as consumers wait for the next generation of Apple's iPhone, a US-based market research and consulting firm said Tuesday.

A total of 1.99 million handsets were shipped to distributors in Taiwan in the second quarter, down 10% from the 2.21 million units shipped a quarter ago and down 0.3% from a year earlier, International Data Corp said in a report.

Smartphone shipments totaled 1.42 million units and accounted for over 70% of the total handset volume, well below the 1.65 million units and 75% share in the first quarter, the report said.

The 14% decline was the deepest quarterly fall ever for smartphone shipments in Taiwan, largely because iPhone sales dipped over 80%, or 300,000 units, from those in the first quarter, according to IDC.

"The slump in Apple's second-quarter shipments could be attributed to the inventory adjustment in channels, which was in line with its positioning ahead of new products," Joey Yen, a Taipei-based senior analyst at IDC, said in the report.

"Other competitors have aggressively launched new phones with large screens since the first half of this year, which also partially hurt the demand for the 3.5-inch iPhone due to the lower convenience of its smaller screen," she said.

In terms of operating systems, Apple's iOS took only 5.2% share in the second quarter, the second lowest since the fourth quarter of 2008 when the iPhone first went on sale in Taiwan, IDC said.

Google's Android system, on the contrary, continued to top the Taiwan market with a 92.7% market share, the highest since it entered Taiwan in the second quarter of 2009, the research firm said.

Microsoft's Windows remained as the third-largest mobile platform, with its market share sliding to 1.0% from 1.4%, IDC said.