The trade of human traffickers is being aided by the internet, says Linda Criddle, who heads a Microsoft unit dedicated to stopping the practice.
Ms Criddle, who is attending the annual Global Summit of Women in Cairo, said the company had set up a team to teach victims and their families how to protect themselves.
Predators were using the anonymity of the Web to contact victims and to make them available to paedophiles around the world. The Microsoft unit is researching methods by which children can be protected and parents warned.
Ms Criddle has written a book, Look Both Ways, a Family Guide to Internet Safety, which will be circulated internationally.
'There is a ring that puts catalogues of children on the internet, describing and showing pictures of them,' she said.
'Paedophiles can order from this catalogue and then extreme measures, even kidnapping, are taken to obtain the children and make them available for a very high price.