Vodafone teamed with Safaricom - in which it has a minority stake - in March 2007 to launch the internal mobile money transfer service M-Pesa, which has already attracted over four million customers.

Using Western Union's processing hub, they now plan to build on the M-Pesa success by introducing cross-border mobile remittances.

During the pilot, participants will be able to send money through Western Union agents in the UK town of Reading to any Safaricom mobile subscriber in Kenya. Recipients can then visit one of 4,-000 M-Pesa agents in Kenya to withdraw their cash, or forward it on to another mobile phone in the country.

Nick Hughes, head, international mobile payments, Vodafone, says: "The successful take-up of M-Pesa in Kenya has clearly demonstrated the demand for easily accessible, secure cash payment services in emerging markets."

Vodafone says increased global migration has led to a significant increase in the flow of funds from expatriate migrant workers who send money home, with the World Bank estimating that Kenya received around $1.3 billion in international remittances last year.

Michael Joseph, CEO, Safaricom, says: "This is another great step for M-Pesa and will benefit many Kenyans all over the world. International remittances form a significant part of the total income for some Kenyans, and the partnership with Western Union will provide Kenyans with an opportunity to receive small values of cash from abroad in a fast, safe and affordable way."

Mobile money transfer services are gaining popularity in developing countries where far more people own handsets than have bank accounts. Earlier this month operator Orange teamed with BNP Paribas to launch West Africa's first mobile payments and money transfer service in the Ivory Coast.