Sir Christopher has consistently refused calls to resign from his BBC post following his appointment in May as BT chairman.
He told guests at a Media Society lunch yesterday, "There is a major conflict of interest between the two organisations. BT is involved in broadcasting discussions, but I will not be involved in them until I leave the BBC in September."
Sir Christopher used the occasion to offer his opinion on who should succeed him in the top job at the BBC. He called on Tony Blair to appoint a controversial successor to him at the BBC.
The frontrunner is the New Labour-supporting Goldman Sachs economist Gavyn Davies. However, his appointment would likely draw considerably fire and fuel the cronyism debate which has dogged Labour since it first came to office in 1997.
A strong candidate to enter the race for the BBC chairman's job is being seen in Richard Lambert, who is soon to step down as editor of the Financial Times.
Sir Christopher has been chairman of the BBC board of governors since 1996 and will remain there until a replacement can be found.