The fertility expert Paul Rainsbury said that his controversial sex-selection service was designed "to end the distress faced by millions of couples unable to create the offspring of their choice".
His announcement is the latest in the continuing controversy over advances in genetics. Earlier this week, the first cloning of a adult sheep was revealed.
Within the next couple of weeks, Mr Rainsbury will offer couples the chance to visit a clinic in Naples, Italy, and undergo in vitro fertilisation treatment while choosing whether they want a son or a daughter at a cost of at least pounds 10,000. He says two British couples have already applied to take part, as well as couples from Italy and Saudi Arabia.
Although the success of IVF itself cannot be guaranteed - the average live birth rate is 14 per cent - the sex of any foetus which survives to birth can be 100 per cent guaranteed. Surplus embryos would be disposed of or given to childless couples.
The process was pioneered at Hammersmith Hospital in west London, but control of a baby's sex is allowed only by the Human Fertilisation and Embryology Authority for health reasons, to prevent genetic disorders, such as muscular dystrophy or haemophilia, being passed on by one sex. Selecting for social reasons is illegal.
Mr Rainsbury said that he had been persuaded to offer such a service after numerous appeals from couples, mainly from the Middle East, desperate for a son. A survey carried out by the Institute of Public Health showed that failure to give birth to a male baby was a significant factor in the high percentage of suicides among Asian women in Britain.
"At one time I was unconvinced about providing such medical assistance," he said. "But as I and my colleagues in the Western world have learnt more about the cultural and economic pressures imposed on such couples the more I have come to believe medical science should be used to mitigate needless anguish and suffering."
Of his critics he said: "Those of us who work in the field of human reproduction have long grown accustomed to censure, usually by people who have no idea of the huge distress caused by infertility and childlessness."
But a spokesman for the Society for the Protection of the Unborn Child said: "It is a step further down the path where the right to a child becomes the right to a particular child, a mentality encouraged by the practice of IVF. It leaves embryos vulnerable to be discarded and it is a flagrant violation of the child's rights".
A spokesman for the pro-life charity Life added: "We are not surprised. It just marks another milestone in the commodification of the baby."
Lord Robert Winston, professor of fertility studies at Hammersmith Hospital, described Mr Rainsbury's claims as "reprehensible".
"There is no question that the government regulatory operation has made it quite clear that they would not want us to do sex selection for social reasons and nor would we," he told the London radio station LBC.