The Church of England is considering whether it should pay reparations for its role in the slave trade, the Archbishop of Canterbury has said.
Dr Williams took part in a procession marking the bicentenary
Dr Rowan Williams told BBC Radio 4's Trade Roots there was "no quick solution" but the Church was beginning to ask and "work at" the question.
The Church, which owned slaves on plantations in the Caribbean, apologised for its role last year.
Sunday was the 200th anniversary of UK legislation abolishing the slave trade.
Dr Williams and the Archbishop of York, Dr John Sentamu, led a procession through London on Saturday to mark the bicentenary.
'Loss of labour'
The slaves owned by the Church were eventually freed in 1833 - 26 years after the abolition of the slave trade in the British Empire.
And the Church received government compensation for the loss of slave labour of almost £9,000.
Dr Williams told Trade Roots that the Church needed to consider whether it should make reparation.
"While it sounds simple to say all right so we should pass on the reparation that was received [when the slaves were freed], exactly to whom?" he said.
"Exactly where does it go? And exactly how does it differ from the various ways in which we try to interact now with the effects of that in terms of aid and development and so forth?
"So I haven't got a quick solution to that. I think we need to be asking the question and working at it. That, I think we're beginning to do."
He said Anglicans needed to acknowledge that they belonged to an institution partly shaped "by terrible things that our forbears did".
Dr Sentamu has called on Britain to make a formal apology for the slave trade.
Tony Blair said on Sunday the country's role was a "matter of deep sorrow and regret". but his statement appeared to fall short of demands from campaigners who say he has not gone far enough.
Radio 4's Trade Roots can be heard at 1100BST on Mon 26, Tue 27 and Wed 28 March 2007 or for 7 days afterwards at Radio 4's website.