As global smartphone shipments hit a historic high of 301.3 million in the second quarter, third-ranked Windows Phone OS' share of that pie stumbled to well below 3%.

Despite shipping for four years, Windows Phone-based devices accounted for only 2.5% of the total smartphone market in the second quarter of 2014, down from 3.4% in the year-earlier period, IDC reported Thursday. Overall Windows Phone shipments for the second quarter totaled some 7.4 million, down 9.4% from the 8.2 million shipped a year earlier, IDC said.

Meanwhile, shipments of Android phones from various manufacturers, including Samsung, HTC, LG and Motorola, surged by 33%, to 255.3 million during the period. Android devices accounted for 84.7% of the overall smartphone market during the period.

Shipments of Apple's iPhone grew by 12.7% to 35.2 million, though its market share of 11.7% was down from 13% a year earlier.

"It's been an incredible upward slog" for Windows Phone and other smaller OS players in the smartphone market," said IDC analyst Melissa Chau in a statement. "Windows Phone has been around since 2010 but has yet to break the 5% share mark."

Windows Phone did slightly better in the second quarter than in the first 2014 period -- though IDC said the sequential improvement was statistically insignificant.

The continuing problem with Windows Phone and other small OS players have is getting partners, mostly manufacturers and developers. Developers tend to work in small shops and can reduce their workload by working with just the two primary smartphone OS ecosystems, Android and iOS, Chau said.

But Windows Phone could sign more manufacturing partners in the second half of 2014, IDC said, including BLU, Micromax, Prestigio, and Yezz. In addition to now owning Nokia, Microsoft is already working with a manufacturers Foxconn, Gionee, JSR, Karbonn, Lava, Lenovo, LG, Longcheer and ZTE.

In late May, IDC predicted Windows Phone would take a 3.5% share of the smartphone market for all of 2014, with 43.3 million smartphones shipped. However, the second quarter shipments of 7.4 million Windows Phones indicates that 43.3 million shipments for the year could be unreachable.

IDC analyst Ramon Llamas said in an interview Thursday that IDC's full-year 2014 smartphone forecast is now being updated. He added that how well Windows Phone performs for the full year depends on how well Microsoft works with new manufacturers as well as the new Nokia unit, officially made part of Microsoft in April.

Since the second quarter ended on June 30, Windows Phone's future has been called into greater question than any time since its birth in 2010.

In July, Microsoft announced it will lay off 18,000 workers, including 12,500 from the Nokia acquisition. It also said it would drop its low-end line of Nokia X Android phones.

Those moves prompted some analysts to question the long-term future of the Windows Phone OS.

A recent Good Technology report found that Windows Phone was used in only 1% of 5,000 enterprises surveyed in the second quarter. By comparison, iPhones and iPads were used in 67% of enterprises, and Android smartphones and tablets in 32%.

The 2.5% Windows Phone Q2 market share reported by IDC was even lower than the 2.7% share reported by Strategy Analytics. IDC's count of 7.4 million Windows Phones shipped was also less than the 8 million Strategy Analytics tallied.

Samsung, the world's biggest smartphone maker that's credited with 29.3% of all Android-power smartphone shipments for the quarter, still has not seen significant impact with the Tizen OS, IDC noted.

BlackBerry volumes were also up slightly in the second quarter over the first, but were 78% lower than a year ago, at 1.5 million smartphones. That puts BlackBerry at 0.5% market share, down from 2.8% in the second quarter of 2013.

The record 301.3 million smartphones shipped in the second quarter was an increase of 25.3% of the 240.5 million shipped in the second quarter of 2013, IDC said.

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