Hazar Imam said he was delighted to announce the engagement.
Prince Rahim Aga Khan holds a BA from Brown University and an executive management degree from the Navarra Business School in Barcelona, Spain. He is involved in poverty reduction efforts, notably micro-credit activities, of the Aga Khan Development Network – one of the largest private systems of agencies fostering social, cultural and economic development in Asia, Africa and the Middle East.
Ms Spears holds a BA in sociology from the University of Washington in her native Seattle. She has a strong interest in arts and architecture.
The couple will be married in a Muslim ceremony. The date of the marriage has not been set yet.