The past year proved as the year that Apple and Samsung intensified their rivalry, while former mobile phone leader Nokia further slid down and continue struggling, reports said.

Virtually, the smartphone battle became the exclusive turf of Apple and Samsung, according to Strategy Analytics.

The former relied on the huge popularity of the iPhone 4 for the better part of 2011 and the iPhone 4S in the last quarter while the latter got its boost on the Galaxy product lines, which Apple tried in vain to prevent from reaching the market.

Powered by Google's Android, Samsung issued both high-end and entry level Galaxy smartphones that by September 2011 had catapulted the South Korean firm, selling millions that analysts attributed to handsets that were cheaper but not lagging in functions and feature.

Apple, however, tweaked the iPhone 4 and days before the demise of co-founder Steve Jobs, unveiled the iPhone 4S in late October, with the virtual assistant Siri, deployed on each units, as the centre piece of the new gadget.

Many tech experts called the iPhone upgrade as anaemic but consumers worldwide seemed not to care as iPhone 4S was snapped up by the millions, in fact selling up to 155 million until the final days of December whittled away.

According to Strategic Analytics director Alex Spektor, from the already astounding 37 million of iPhone 4 units that were sold in the last quarter of 2010, Apple saw its sale surging by 128 percent in the last three months of 2011.

On the other hand, Samsung's combined sales of all Galaxy smartphones reached 36.5 million, not even a third of Apple's sales figures, while Nokia only sold 19.6 million handsets to secure the third spot.

Clearly by the year end, more people around the world were using Apple smartphones while its competitors were left to fight it out with the remaining market shares.

"Apple overtook Samsung to become the world's largest smartphone vendor by volume with 24 percent market share," Spektor said.

The American firm's further success was credited to Apple's strategy of penetrating more market in 2011.

"Distribution of the iPhone family expanded across numerous countries, dozens of operators and multiple price points," the Strategic Analytics report noted.

Tim Cook reported to Apple shareholders last week that iPhone 4S outsold other phone brands and models in big ways during the lucrative season that spanned the months of October though December.

Yet for the year-to-year smartphone sale, Samsung bested its closest foe by capturing 20 percent of the market share for 2011 and selling 94.7 million of Galaxy handsets, most prominent of which were the Galaxy SII, the Galaxy Nexus and the Galaxy Ace, all year round.

Apple came close but still short by over a million at 93 million units, according to Strategic Analytics.

The sales numbers achieved by the fierce rivals signal that a more heated competition environment will shape up between the two this year.

"And Samsung is now well positioned alongside Apple in a two-horse race at the forefront of one of the world's largest and most valuable consumer electronics markets," Strategic Analytics said.

As for Nokia, its share of 33 percent recorded in 2010 shrunk to 16 percent at the end of 2011, with analysts blaming only the Finnish company for failing to innovate early and wow the consumers with better handsets.

Nokia reported a net loss last week by top honcho Stephen Elop is optimistic that this year will mark the company's turnaround from its misfortunes.

Touting an overhaul of its ecosystem, Elop stressed that its new partnership with Microsoft, forged last year, will be the platform that will fuel Nokia's journey in the years ahead.

Nokia is banking on its new Windows-powered Lumia lines, which only sold more or less a million last year following its launch in the last quarter, leaving analyst cautious enough to catch on Elop's optimism.