Supply of Nokia's Lumia 920 was getting scarce in the past few weeks due mainly to solid demands and apparently the Finnish mobile phone maker was caught off guard by the overwhelming reception generated by its new flagship smartphone.

In a research note published Monday by market research firm Canaccord Genuity, it appeared that the Lumia 920 started on a rock-solid footing in the U.S. market, its sales numbers decent enough to come behind the bestselling smartphones in America as of November this year - Apple's iPhone 5 and Samsung's Galaxy S3.

"Our checks indicated the Lumia 920 was the top-selling Windows smartphone at AT&T and number 3 selling device at that channel," Canaccord Genuity analyst T Michael Walkley was quoted by BGR News as saying.

That same note indicated too that the Nokia smartphone, powered by Microsoft's Windows Phone 8, has been drawing remarkable attention from key markets around the world, including Europe, where the handset was recently reported by Bloomberg as enjoying an LTE advantage over the iPhone 5.

"The Lumia's LTE connectability is going to help Nokia stand out to holiday shoppers," a Nokia official was reported by Bloomberg as saying, adding that both the Lumia 920 and Lumia 820 are LTE-compatible with at least 12 networks in Western Europe.

Unfortunately, such headstart was squandered a bit by Nokia as it struggled to meet orders for the 920, cause of which was likely on cautious efforts by the firm not to over-produce the WP8 handset, analysts said.

"Limited initial supply was cited as the reason for early post-launch stock-outs at some carriers versus overwhelming demand," Mr Walkley said in his note.

He also expressed fears that it could prove lost opportunity for Nokia to rake in as much cash as possible with the Lumia 920, adding that consumers' interest of the gadget could eventually wane in the months ahead as fresher handsets hit the international market.

One possible competitor for the 920 come the early months of 2013 is Samsung's Galaxy S4, which is being rumoured to join the million-selling Galaxy S pedigree as early as the first quarter of next year.

Yet for now, Nokia can take comfort on robust sales figures from key markets which pointed to the fact that the Lumia 920 is developing into a smartphone brand that spells more good news for the tech firm, BGR's Zach Epstein said.

"We wondered if (the Lumia 920) was compelling enough to attract consumer attention. In these early days, the answer appears to be 'yes'," Mr Epstein said.

But as other analysts have initially observed, Nokia could ill-afford to relax just because the 920 has been registering fantastic sales figures. Its Windows rival, HTC's Windows Phone 8X, is also doing relatively well, Mr Walkley said.

In fact, the HTC 8X is outperforming the Lumia 820 in the same U.S. market based on data provided by T-Mobile and Verizon, the Canaccord analyst added.