Nokia Oyj , the world's top cellphone maker, unveiled four new cheap models and a bicycle charger in a move to protect its dominance in emerging markets.

Nokia said the 15-euro charger was targeted at developing countries with limited access to electricity but could catch on in Europe where cycling to work and to the shops is common.

"In cities like Amsterdam for instance, where bicycles are probably the most common means of transportation, the supply of free, environmentally friendly power is pretty much limitless," said spokesman Leo McKay.

The charger, the first of its kind from a mobile company, would replenish a flat battery in just over two hours of cycling at around 15 kph, Nokia said.

Nokia controls more than 50 percent of phone sales in India and Africa and has a strong position in most other emerging markets.

Ben Wood, director of research at CCS Insight, said Nokia's new phones would help it keep ahead of intensifying competition from Chinese vendors in the ultra low-cost segment.

"With all the focus on its smartphone woes it is easy to forget that Nokia is a power house in entry level products."

The prices of the four new phone models, excluding possible operator subsidies and local tax, range from 30 euros ($36.9) to 45 euros.

Two of the new phones, including the cheapest 30 euro model, will enable usage of two different SIM cards -- helping sharing a phone between family members or friends.

Nokia has struggled to keep up with rivals like Apple and RIM in the high-end of the market, and its ailing smartphone offering has hurt the stock price over the last few months.

Separately Nokia also unveiled the Nokia E73 Mode messaging phone model which will exclusively be sold by Deutsche Telekom 's T-Mobile in the United States - the market where the Finnish handset maker's smartphones have struggled the most. (Reuters)