Microsoft's new Windows Phone platform won instant support from major manufacturers on Wednesday when China's ZTE and Taiwan's HTC Corp pledged to launch smartphones running the software.

The software giant had stepped up its push into the cellphone market a day earlier with the launch of the new Windows Phone software, code-named Mango. It hopes a host of new features will help it close the gap on smartphone leaders Google Inc and Apple Inc.

Microsoft has struggled for years to gain support from mobile phone manufacturers. All vendors in total sold just 1.6 million Windows Phones last quarter, giving it a market share of below 2 percent. Google and Apple together control more than 50 percent of the smartphone market.

Windows Phone got a major boost in February when Nokia, the largest phone vendor by volume, said it would swap its own Symbian platform for Windows Phone.

On Wednesday ZTE said it would roll out smartphones running updated Microsoft software later this year in Europe, and in 2012 in the United States.

And Taiwanese smartphone maker HTC plans to bring out some models based on Microsoft's new software, its Chief Executive Peter Chou told Reuters on the fringes of an internet conference in Paris.

We are very committed to Windows phone products, he said.

Analysts said Microsoft needed all the support it could get from handset vendors.

Increased support and competition can only help Windows Phone. It desperately needs more aggressively priced devices and a substantial promotional push to coincide with the Mango release, said Geoff Blaber, an analyst with CCS Insight.

ZTE, which is known for its aggressive entrance into the telecom equipment market, could help to boost Microsoft's position among cheaper smartphones.

ZTE expects to ship more than 80 million handsets this year, up by a third from last year's 60 million units, an executive told Reuters earlier this year. Key markets for ZTE's handsets include China, Europe and the United States.

In the fourth quarter of 2010, ZTE became the fourth-largest handset maker by unit shipments globally, ranking behind Nokia, Samsung Electronics Co Ltd and LG Electronics Inc, market research group IDC said.

(Reporting by Lee Chyen Yee and Huang Yuntao in Shenzen, Georgina Prodhan in Paris and Tarmo Virki in Helsinki; Editing by Alexander Smith)