William, Kate expecting third child

Britain's Prince William and his wife Kate are expecting their third child, the Kensington Palace announced today.

William and Kate, the Duke and Duchess of Cambridge, already have two children -- Prince George and Princess Charlotte -- aged four and two.

"The Duke and Duchess of Cambridge are very pleased to announce that The Duchess of Cambridge is expecting their third child," the palace said in a statement.

Kate is suffering from Hyperemesis Gravidarum, a form of severe morning sickness, and will not carry out her engagements today, it said.

The Queen and both families are said to be "delighted with the news".