Boston-based market research firm Strategy Analytics estimates that worldwide cellular phone subscriptions will hit 2.5 billion by the end of the year. The emergence of third-world countries and the growth of high-speed 3G networks are the two main factors that are fueling the upsurge, the firm said.

Most of the growth comes from emerging economies like Russia, India and Indonesia - all who have seen 40-50 percent growth in the number of subscribers over 2004. According to Phil Kendall, Director of the company’s Global Wireless Practice, African nations should take experience the same growth this year.

Strategy Analytics believes that the switch to high-speed third-generation cellular networks will also enhance growth. The firm believes that Europe’s switch to W-CDMA, along with the US going to EV-DO will more than double the current subscriber base.

Strategy Analytics believes subscriber revenues should hit $800 Billion annually by the end of the decade.