The global market share of Windows Phone (WP)-based smartphones is expected to continue declining before Microsoft Mobile launches its next generation WP phone in the second half of 2015, according to sources at Taiwan's handset supply chain.

The share of WP phones has continued to fall because the specifications and functionality of high-end WP models are not outstanding, while the price/performance ratios of entry-level and mid-range WP phones are not as strong as those Android-based smartphones, said the sources.

Shipments of WP phones totaled nine million units in the third quarter of 2014, accounting for 3% of the global smartphone market, down from 3.6% of a year earlier, according to Gartner. During the same period, Android- and iOS-based smartphones held 83.1% and 12.7%, respectively, of the market share.

Although a number of China-based and regional handset makers have agreed to support WP platform, most of these suppliers have not yet released WP-based models on concern of popularity of WP phones, indicated the sources.

China-based Huawei has said that it plans to withdraw from the WP camp, while Samsung Electronics and HTC have released WP-based models only in the US and other designated markets.

However, the sources pointed out that Microsoft Mobile plans to roll its next generation WP phone, the Windows 10, in the second half of 2015, which may come out with improved WP platform optimizing its newly developed "One Windows" strategy.