Media playback is unsupported on your device Media caption Josef Ackermann says bankers have a social responsibility

The chief executive of Deutsche Bank has warned of a "social time bomb" from wealth and income inequality.

Josef Ackermann, who also heads the Institute of International Finance which represents the world's banks, told the BBC that bankers had a responsibility to be philanthropic with their bonuses.

He is due to receive a partially deferred bonus of 8m euros (£6.6m).

However, he said, he felt people in his position had to make a contribution.

"We have a social responsibility, because if this inequality increases in income distribution or wealth distribution we may have a social time bomb ticking and no-one wants to have that."

However, Dr Ackermann said he "preferred not" to talk about philanthropic gestures.

Pay disclosure

His comments come as an annual survey of chairman and non-executive directors, who sit on company boards, carried out by head-hunters Hanson Green and Directorbank found just 32% of chairman think the way top executives are paid is working.

The survey of 298 chairman and 190 non-executive directors found 45% agreed with a proposal that the ratio of chief executive pay to average employee pay should be disclosed in company reports.

Some 94% agreed that companies should have the right to claw back pay if performance changes over the medium term.

The firms said that total remuneration for the average FTSE chief executive rose by 13% in 2011.

The latest figures from the Office for National Statistics showed weekly earnings rose at an annualised rate of 1.9% in the three months to November 2011.