Two of the world’s richest men, with bank balances that rival the gross domestic product of small countries, are joining forces to wage war against a common enemy — the tobacco industry.

Bill Gates, the co-founder of Microsoft, and Michael Bloomberg, the Mayor of New York City, are making a combined investment today of $500 million (£250 million) to try to reduce smoking in countries such as China and India and to help to prevent a “tobacco epidemic” in Africa.

The billionaires, through their eponymous charities, intend to lobby governments in Asia, Africa and South America to increase taxes on cigarettes, implement smoking bans and raise awareness of health risks.

Nearly five million people worldwide a year — almost 14,000 every day — die from tobacco-related illness, more than are killed by any other single agent. Unless urgent action is taken, they say, as many as one billion people — more than two thirds of these in the developing world — could die this century as a result of smoking.

As rates of smoking have decreased in the developed world, tobacco companies have concentrated their advertising and marketing resources on the developing world.

Many of the companies have argued that they are not trying to addict new smokers but are trying only to convert adults who are smoking inferior local brands. However, the World Health Organisation released a report this year that concluded that the industry was targeting teenagers and women. The developing world is also used as a “dumping ground” for much of the inferior quality tobacco grown by the companies.

One aspect often cited as a reason why many low and middle-income countries have resisted calls to ban advertising is that they enjoy the revenues generated from tobacco taxes.

The Bloomberg Initiative to Reduce Tobacco Use, which was established in 2005, has to date committed more than $375 million towards projects aimed at reducing passive smoking and helping smokers to give up.

The Bill & Melinda Gates Foundation, founded in 2000 by Mr Gates and his wife, and rated as the largest philanthropic organisation of its kind in the world, is now to contribute an additional $125 million over five years.

The Bloomberg Initiative will provide tobacco-control funds to low and middle-income countries through competitive grants. Particular emphasis will be on funding programmes in China, India, Indonesia, Russia and Bangladesh, which together account for about half of the world’s smokers.

“When I announced this initiative, I said that I hoped others would step forward,” Mr Bloomberg said yesterday. “I’m delighted Bill and Melinda Gates are supporting one of the most important public health efforts of our time.”

Mr Gates said: “Tobacco-caused diseases have emerged as one of the greatest health challenges facing developing countries. The good news is, we know what it takes to save millions of lives, and where efforts exist, they are working. We are pleased to join with Mayor Bloomberg, who has made the fight against tobacco a priority in New York City and around the world.”

The move marks a change in focus for the Gates foundation, which has largely focused on combating infectious diseases such as HIV/Aids in the developing world.

The tobacco industry produces more than 5,400 billion cigarettes a year. The biggest market is China, where more than 300 million smokers consume about 2,200 billion cigarettes a year, 40 per cent of the global total.

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