The number of mobile phone subscriptions in the world will reach four billion by the end of the year driven by growth in developing economies, the International Telecommunications Union said Friday. ‘Since the turn of the century, the growth of mobile cellular subscribers has been impressive,’ the ITU said in a statement. The ITU stressed however that its estimate does not mean that four billion individuals each have their own mobile phone, as many people in developed countries have more than one. Earlier this year the ITU said that the number of mobile phone subscriptions topped 3.3 billion by the end of 2007. Continued progress in 2008 is chiefly due to the growth in major developing markets such as Brazil, Russia, India and China. ‘These economies alone are expected to account for over 1.3 billion mobile subscribers by the end of 2008,’ the ITU said. China surpassed the 600 million mark by mid-2008, becoming the world’s biggest mobile phone market, while India had around 296 million subscribers by the end of July. ‘Market liberalisation has played a key role in spreading mobile telephony by driving competition and bringing down prices,’ the ITU noted.