Later in the session, Mr Diamond paid tribute to how the G20 - which France is the current President of - to the financial crisis.
"We should thank the regulators," Mr Diamond said.
"The G20 came together... that was very beneficial for the banking sector."
Christine Lagarde responded by saying that "good financing and sensible compensation" would be better forms of thanks.
...
Mr Sarkozy also sparred with a bank boss in his session earlier this week.
JP Morgan boss Jamie Dimon urged him to avoid introducing regulation "out of anger" while France was head of the G20.
The French president hit back, saying banks had done things which "defied common sense" and should not resist more regulation.
"If people present me as obsessed with regulation, it's because there is a need for regulation," Mr Sarkozy said.
http://www.bbc.co.uk/news/business-12315791