Earl Spencer is understood to have employed the services of renowned divorce lawyer Baroness Shackleton of Belgravia, after announcing the end of his third marriage.

Baroness Shackleton, dubbed the "steel magnolia" for her combination of resoluteness and charm, previously represented King Charles, then the Prince of Wales, when he divorced Spencer’s sister Princess Diana back in 1996.

Industry guide Legal 500 describes the lawyer as “a demon negotiator” with other high-profile former clients including Sir Paul McCartney and Prince Andrew.

Spencer, 60, instructed her after announcing he and Canadian philanthropist Karen Gordon, 52, were planning to divorce after 13 years of marriage, The Times reports.

“It is immensely sad," he told The Mail on Sunday. "I just want to devote myself to all my children, and to my grandchildren, and I wish Karen every happiness in the future.”

READ MORE: Spencer breaks silence after announcing divorce from his third wife

The former couple got married in June 2011 on the grounds of Althorp, which holds a special in Charles's heart as it's the burial place of his beloved sister Diana.

Canadian Gordon, 52, is the founder and chief executive of Whole Child International, an LA-based charity that works to improve the lives of orphaned, abandoned and abused children.

Spencer and Gordon, who met on a blind date in LA in 2010, were married in June 2011, just four months after he proposed.

They have a 12-year-old daughter together named Charlotte Diana, in tribute to the Earl's late sister.

Karen has two daughter from a previous marriage to Hollywood producer Mark Gordon, while Spencer has seven children in total.

The news has also come at a hard time for Ms Gordon, as she revealed earlier this week that her father had passed away from Alzheimer's disease.

She posted on social media: "My father passed away today after a long battle with Alzheimer's. I was happy to be there to support my mother and brother who have been doing the bulk of the heavy lifting in dealing with his care here on Vancouver Island."

Earl Spencer who had a close relationship with his sister Diana, has also remained on good terms with Prince Harry, attending the Invictus Games 10th anniversary service with his nephew last month.