WASHINGTON - Billionaire philanthropists Bill and Melinda Gates have announced they are divorcing after 27 years of marriage, raising questions over how they will split their fortune and the direction of one of the world's most powerful charity organizations.

The couple, with a joint fortune estimated at $130 billion, have channeled billions into charitable work around the globe via their hugely influential Bill & Melinda Gates Foundation. They said they would continue their joint work on the foundation, which funds programs in global health, gender equality, education and other causes.

"After a great deal of thought and a lot of work on our relationship, we have made the decision to end our marriage," they said in a joint statement, posted on each of their official Twitter accounts on Monday.