Associated Press
FILE - In this Feb. 2, 2012 file photo, New York City Mayor Michael Bloomberg presents the Fiscal Year 2013 preliminary budget in New York. Bloomberg on Thursday, March 22, 2012 is expected to announce he will commit $220 million to his charity to go toward programs that reduce tobacco use in developing countries (AP Photo/Mary Altaffer, Pool, File)

NEW YORK — Michael Bloomberg, the billionaire who has made reducing smoking one of his signature causes as mayor of New York City, is committing $220 million to his charity to go toward reducing tobacco use in countries that are home to millions of smokers.

He announced his four-year commitment to Bloomberg Philanthropies at the 15th World Conference on Tobacco or Health in Singapore on Thursday. The new commitment will bring the total amount he has directed to his eponymous charity to over $600 million for anti-smoking efforts since 2007.

"Tobacco kills every day, so we need to keep the fight moving forward and keep the momentum going," Bloomberg said in a statement.

Bloomberg, who made his fortune in the financial services industry, was ranked fifth on the Chronicle of Philanthropy's list of 50 of the "most generous donors" for 2011.

His new commitment will go toward initiatives including smoke-free laws, graphic pack warnings and raising taxes, charity officials said. The focus will be on country-level change, particularly in China, India, Indonesia, Russia and Bangladesh, which officials say account for the largest share of tobacco use in the world.

As mayor of New York City, Bloomberg has steered public health policy to ban smoking in restaurants, bars, parks and beaches; launch numerous advertising campaigns to alert consumers to the hazards of tobacco use; and raise the price of cigarettes through taxes.

James Colgrove, a professor at Columbia University's Mailman School of Public Health and author of "Epidemic City: The Politics of Public Health in New York," said there was a great deal of evidence supporting the tobacco reduction initiatives that Bloomberg Philanthropies and the city have pursued.