For all of us in mobile marketing, we’re always keeping an eye on which device and operating system is leading the pack nationally and internationally. While globally both the iPhone and Android phones, in terms of sales figures alone, are not as hot as they are in the US, the two are fighting each other for international market share. In February, for the first time, the Google Nexus One outsold the iPhone globally by 16%.

The Nexus One, which can be used on any carrier as opposed to the iPhone, seems to be catching on with its open source Android operating system. The report released today by 3G.uk notes that the trend in Nexus One growth is expected to continue, despite talk by many that claim the phone is a hardware flop.

Peter Chou, CEO of NexusOne designer HTC, says it was a success. And maybe the latest sales figures are proving his unlikely conclusion. Earlier the phone has been plagued by customer service troubles, delayed overseas launches, and even poor early sales compared to its competitors.

Chou spoke with Forbes’ Elizabeth Woyke this week at the CTIA Wireless conference in Las Vegas. He said that the Nexus One is a success because of its innovative design that will attract other design and manufacturing business for HTC. But beyond additional business, he’s pleased with the NexusOne sales. “Considering Google didn’t do [standard] retail or marketing for it, the Nexus One is doing pretty well,” he told Forbes.

Worldwide mobile phone sales to end users totaled 1.211 billion units in 2009, down .9% from 2008, according to last month’s Gartner report. However, in the fourth quarter of 2009, sales grew 8% year over year. Globally, in 2009 Symbian led the pack in smartphone OS sales with 46.9% market share, down from 52.4% in 2008. Research in Motion came in second, with a 19.9% market share. The iPhone OS came in third, with 14.4% market share, compared to Android in sixth after Microsoft Windows Mobile and Linux, with just 3.9% market share.