Princess Diana's brother Charles Spencer engaged

Princess Diana's brother Charles Spencer is to marry in the summer.

The uncle of future British monarch Prince William - who himself will be marrying long-term partner Kate Middleton on April 29 - has become engaged to Canadian partner Karen Gordon and the pair plan to wed in a private ceremony on June 18.

A statement read: "Charles, the ninth Earl Spencer, is delighted to announce his engagement to Karen Gordon, a Canadian philanthropist who is the Founder and CEO of Whole Child International."

The event will take place at Althorp, England, the ancestral home of the Spencer family, and close friends and relatives are set to attend.

The announcement comes just four months after he ended his engagement to Lady Bianca Eliot.

Charles, 46 - best known for the moving tribute he paid to his sister Diana at her funeral in 1997 - has been married twice before, first for eight years to model Victoria Lockwood and second to Caroline Freud, with whom he split after eight years of marriage in 2009.