The digital divide between rich and poor countries is narrowing as mobile phones and internet use become more available, but the developing world still lags far behind, according to a new United Nations report.

The United Nations Conference on Trade and Development (Unctad) said mobile phone subscribers had almost tripled in developing countries over the last five years, and now make up some 58 per cent of mobile subscribers worldwide.

"In Africa, where the increase in terms of the number of mobile phone subscribers and penetration has been greatest, this technology can improve the economic life of the population as a whole," it said.

The report said mobile phones were the main communication tool for small businesses in developing countries, reducing costs and increasing the speed of transactions.

"Mobile telephony provides market information for, and improves the earnings of, various communities, such as the fishermen of Kerala, the farmers of Rajasthan, the rural communities in Uganda, and the small vendors in South Africa, Senegal and Kenya," it said. Internet use and penetration continue to increase worldwide, but developed countries still account for the majority of internet users and have the highest penetration.

"In 2002, internet availability in developed countries was 10 times higher than in developing countries; in 2006, it was six times higher," the report said.

Developed countries also continue to lead internet subscriptions worldwide, and the gap in terms of internet broadband penetration has widened since 2002, it said.

Unctad said the revolution in information and communication technology was spreading to the developing world, but more needed to be done to make sure poorer countries reaped its opportunities in growth and development. Among its recommendations were that countries invest more in human capital and infrastructure and better regulation of cyber laws.