The troubled East of England Ambulance Service (EEAS) has appointed a temporary boss, two months after its chief executive resigned.
The service has struggled with delayed response times and low staff morale.
EEAS said Dorothy Hosein was a "fantastic choice" for interim chief.
It praised her "wealth of experience at partner trusts" and said she would remain in post until a substantive chief executive was appointed.
EEAS is one of 10 ambulance trusts in England. It serves six million people across Bedfordshire, Cambridgeshire, Essex, Hertfordshire, Norfolk and Suffolk.
Mr Morton apologised in May after it was revealed that 22 patients had suffered some form of harm - three of them severe - in ambulance delays caused by "unprecedented" winter demand.
At the time of his resignation, former health minister Norman Lamb described the move as "long overdue" and said the service had "toxic culture".
EEAS did not comment at the time of his resignation, but released a statement on Thursday confirming Ms Hosein's appointment.
EEAS chairman Sarah Boulton said: "I'd like to thank everyone who has supported Robert throughout his three-year tenure, a period of EEAS's life that has seen a focus on excellence in patient care, innovation through partnerships, securing millions of pounds of investment into EEAS, and much more.
"With Dorothy, the united board-level team will further strengthen our service and help EEAS remain focused on our patients and the care we provide for them."
Ms Hosein most recently worked as an interim managing director of Mid Essex Hospitals and is a management consultant for the NHS.
She spent almost three years at the Queen Elizabeth Hospital in King's Lynn, as a chief operating officer and then chief executive, leaving in April 2017.