As part of her new role, she will oversee sales in Bonhams' global offices in London, New York, Hong Kong and Los Angeles.
Ghika has had 25 years of experience working at Bonhams. She was appointed director of jewellery for UK and Europe in 2007.
Matthew Girling, global CEO and former global director of jewellery at Bonhams, said: “I have worked with Jean for more than 21 years and I am delighted to hand over this global role to her. She has demonstrated excellent business acumen in her current role and has been instrumental in giving strategic direction to the UK and European fine jewellery.”
Bonhams said Girling will remain closely involved with the jewellery department and will assume a ‘chairman emeritus’ role for fine jewellery. He will also continue to take key jewellery auctions in London, New York and Hong Kong.
Ghika joined Bonhams in 1992 and became the specialist in charge of fine jewellery sales at Bonhams Knightsbridge in 1996, before being promoted and moving across to Bonhams New Bond Street in 2004.