In today's news from BBC World Service:
Slim, Gates and Spain pledge $150m to fight disease
Bill Gates and Carlos Slim each gave about one-thousandth of their fortunes
Two of the world's richest men and the Spanish government have pledged $150m (£101.7m) to battle disease and improve health in Central America and Mexico.
Carlos Slim and Bill Gates are to fund a project jointly with Spain aimed at improving nutrition and maternal health and fighting dengue fever and malaria.
The two men and Spain's Princess Cristina announced the project in the Mexican capital, Mexico City.
The project also aims to reduce infant mortality and boost vaccination rates.
The "2015 Meso-American Health Initiative" will benefit Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua and Panama.
The three parties will each donate $50m.
Worth an estimated $53.5bn, Mr Slim - a Mexican telecom mogul - is the world's richest man, according to this year's Forbes magazine "rich list". Mr Gates, founder of Microsoft, is said to be worth $53bn.