China, India and Africa are leading the world when it comes to mobile phone subscription growth, according to new research.

In-Stat reported today that worldwide cellular subscriptions continued to expand rapidly in 2007, but growth rates are set to fall this year as some areas approach saturation.

A relatively slow global economy is also expected to hinder subscription growth.

"India and China subscription numbers are growing at a fast clip as more of the population gets their first cellphone, and often their first phone of any kind," said In-Stat analyst Allen Nogee.

"Most of these are low-end GSM phones, but even some of these are starting to incorporate more high-end features."

The number of worldwide cellular subscriptions in 2007 grew by 667.6 million over 2006, according to the In-Stat report.

The study predicts that 2008 subscription growth will be only 382.5 million more than 2007's growth.

By 2012, yearly growth in subscribers is expected to decrease to only 163 million per year, roughly twice the population increase projected in that year.