Taiwan's HTC, which derives most of its revenue from phones based on Google Inc' Android software, is currently facing a sharp sales decline as it struggles to compete with iPhone maker Apple Inc and Android rivals such as Samsung Electronics.

HTC will face a stiff battle with smartphone makers Samsung and Nokia Oyj, Microsoft's main handset partner, in the market for phones using Microsoft Windows Phone 8 software.

But Mackenzie said on Thursday that HTC Windows devices will stand up well against its bigger rivals. Nokia did not name any wireless service provider partners when it unveiled its flagship Windows device at a New York event on Wednesday nor did it even give any general indication of operator support.

In comparison Mackenzie said his company has firm commitments from operators to sell its Windows Phone 8 devices.

"I feel very strongly we've got very concrete carrier support in every region around the world including the United States and I'm not talking about just one carrier," the executive told Reuters. "Our plan is to go big on Windows 8."

Mackenzie declined to give specifics on where and when the phone would be sold.

But he did promise that Taipei-based HTC would come out with "a unique (industrial design) language for Windows phones, a language that can be held up by Microsoft as a flagship."

In comparison, he said, other Windows phones makers who also produce Android devices "haven't typically given their A plus designs to Windows phones."

"They've been designating those to Android," he said.

While Android phones generate the bulk of HTC's revenue today, Mackenzie said it would like to see "a more balanced portfolio" in terms of Android and Windows revenue.

"That wouldn't mean we'd want to dial back on Android," he said. "We want to grow Android and grow Windows at the same time."

However, this could be a tough job. While HTC's One-branded Android phones unveiled earlier this year have been enjoying good reviews by analysts and tech blogs, this has not been reflected in its sales.

After its profit fell by more than half in the second quarter, HTC on Aug 3 forecast a third-quarter revenue decline of as much as 23 percent, which was much worse than analysts had feared.

Earlier on Thursday HTC said its August sales were weaker than its July sales.

But Mackenzie said that he sees HTC's current problems as "temporary" and that he hopes to turn the company's fortunes around with better marketing of its brand and its devices.

"We have to get more efficient with the dollars that we're spending and turn every dollar into five," he said, while promising to use social media and online advertising to greater effect in its marketing. "It's about being more bold."

(Editing by Steve Orlofsky)

• A Permanent Economic Emergency