HTC sees '09 U.S. phone sales up 50 pct

*Sees U.S. phone sales volume up at least 50 pct this year

*Sees U.S. launch of Hero Android phone in the fall

*Sees strong growth of Windows-based phones

(Adds executive quotes, background details)

NEW YORK, June 24 (Reuters) - HTC Corp (2498.TW) sees U.S. phone unit sales increasing by "at least 50 percent" this year, boosted by devices based on Google Inc's (GOOG.O) Android system, the head of its U.S. business said on Wednesday.

"I expect to grow U.S. volume by at least 50 percent from 2008 to 2009," Jason Mackenzie, vice president for HTC America, told Reuters in an interview, noting that this would imply sales of about 6 million phones this year.

In comparison, Mackenzie noted that HTC's chief executive had announced expectations for volume growth of 20 percent on a global basis for the company this year.

Part of the reason for the faster U.S. growth may be attributed to strong interest in smartphones here and the fact that HTC's brand is longer-established in overseas markets.