BRUSSELS (AP) -- The appointment of Luxembourg's top banker to a top post at the European Central Bank left it looking a lot like an Old Boys' Club on Friday.

After the European Union leaders picked Yves Mersch in the dead of night Thursday, overriding the objections of its parliament, it left the ECB executive board with six men out of six, and an all-male 23-strong governing council.

"EU heads of state also insulted half of the population of Europe made up of women by suggesting that there is no one suitable to occupy such a senior banking role," said Guy Verhofstadt, the leader of the liberal ALDE group in parliament.

And even though President Francois Hollande backed Mersch for the post, he promised that France would change its ways.

"I make the commitment that for all the upcoming appointments, France will have special attention to balance," Hollande said after the EU summit.

Mersch's appointment to the board was originally blocked in October by the European Parliament to protest the lack of women among the ECB's top executives.

No one has disputed Mersch's suitability for the role, but the appointment stands in stark contrast to efforts made by the EU to bring more women into leading roles in business and politics -- moves that have included proposing 40 percent quotas for the boards of publicly traded companies.

"The family photo of the ECB looks as absurdly anachronistic as that of the ruling presidium of the Chinese communist party," Verhofstadt said.

The heads of government were within their rights to overrule the EU Parliament. Spain was the only nation among the 27 to oppose the appointment.

"This is not a good step," said European Parliament President Martin Schulz.

However, other members of Parliament argued that, with the three-year financial crisis gripping Europe, this was no time for gender niceties. The ECB is confronting a heavy workload during the eurozone debt crisis, with missions to verify bailed-out countries' compliance with their loan agreements.

"Quality must take precedence over sex ratio and discussion," said Werner Langen of the EVP Christian Democrat group.

Mersch was nominated by European governments after extensive political horse-trading over the spot vacated when Jose Manuel Gonzalez-Paramo's term expired May 31. The seat has been vacant since then.

It was the second time in as many months that gender balance in boardrooms took center stage at the EU. A proposal to make more women on the boards of European companies mandatory had to be watered down to gain approval of the full European Commission. It still needs the approval of the Parliament and the Council, which is composed of the 27 EU heads of state and government -- the same group that approved Mersch this time.

Since it started in 1999, the ECB has had one woman on its board -- Gertrude Tumpel-Gugerell, whose term ended in May 2011. There are no women among the 17 national central bank heads who, together with the executive board, make up the 23-member rate-setting council.

There is overall backing for better gender balance in the EU's most powerful financial institution, from ECB President Mario Draghi to EU President Herman Van Rompuy. But for too many the timing was wrong.

After the summit decision, it could be 2018 before a vacancy on the ECB board comes open again.