HELSINKI, FINLAND - Nokia unveiled two new high-end phone models, the N79 and the N85, as the world's top cellphone maker battles against increasing competition from the likes of Apple and Samsung.

The news lifted shares in Nokia more than 2 percent on Tuesday as it reassured investors the company was on track to refresh its offering for the key Christmas sales period.

"Nokia sailed through first half of the year with little changes in its phone portfolio. Now the portfolio renewal has started and this should boost profitability," said Pohjola analyst Hannu Rauhala.

Newer and more expensive models usually have higher profit margins than older and cheaper phones.

The N79 and N85 models will go on sale in October. Both new phones, upgrades of Nokia's older models, will have 5 megapixel cameras and pre-loaded games.

The N85 will retail for 450 euros ($930), excluding operator subsidies and taxes, and the N79 will go on sale for 350 euros.

Nokia, which controls 40 percent of the global cellphone market, has an even higher market share among the most expensive phones, helped by the success of its flagship N95 model.

"All manufacturers are trying to sustain or extend their high-tier device portfolios because of the higher margins they offer," said Ben Wood, research director at CCS Insight.

"Furthermore in saturated markets, in Western Europe and North America replacement sales depend on offering consumers something compelling over and above voice and text," Wood said.

Since last year Nokia's leading position has been under attack from sleek touch screen models from LG Electronics, Samsung and Apple.

Nokia is set to come out with its first touch screen phone, codenamed "Tube", this year. --REUTERS