The head of Germany's largest bank, Deutsche Bank, has caused a row by saying that appointing more women to its executive board would make it "prettier and more colourful," a press report said.

Amid a debate on whether Germany should set quotas for women on the boards of major groups, Josef Ackermann acknowledged there were none on the bank's executive committee, a subordinate body to the board of directors.

"But I hope it will be prettier and more colourful one day" when more women are named, business daily Handelsblatt quoted Ackermann as saying.

Ilse Aigner, the conservative German minister for agriculture and consumer affairs, shot back in the newspaper, saying: "Those who like pretty and colourful things should go take a walk in a field of flowers or a museum."

Deutsche Bank's chief spokesman said Ackermann's remarks had been taken out of context and that he was "a gentlemen from the old school."

Germany's ruling coalition is divided on the idea of introducing quotas to correct a flagrant under-representation of women on corporate boards, an option both Chancellor Angela Merkel and Ackermann oppose.

Women represent 44.3 percent of all Deutsche Bank staff but only 16.1 percent of senior managers, Handelsblatt said.