UPDATE 1-EU Parliament leaders to reject Mersch for ECB

* EU Parliament in row over gender bias at ECB

* Yves Mersch to have hearing with parliament Oct. 22

* Mersch likely rejected on gender grounds

* ECB to uphold Mersch's candidacy

(Updates up with quotes, details)

By Claire Davenport

BRUSSELS, Oct 11 (Reuters) - The European Parliament is set to reject Luxembourg central banker Yves Mersch's appointment to the European Central Bank's executive board on grounds that he is a man and insufficient efforts have been made to appoint a woman.

The leaders of six of the largest political groupings in the European Parliament have agreed to reject Mersch, 63, on grounds of systemic gender bias at the ECB, a statement from one of the leaders said on Thursday.

A hearing into his candidacy will still go ahead on Oct. 22, but Sylvie Goulard, a French liberal parliamentarian said that unless EU member states decided to withdraw Mersch's candidancy, the parliament had no option but to reject him.

"The hearing should take place on October 22nd but a negative recommendation would be adopted, based on the failure by the Council to respect the demands laid down," she said in an emailed statement.

"No judgement would be made on the competences of the candidate," she added.

In September, the lawmakers postponed Mersch's appointment indefinitely by putting off his cross-examination in protest at what they called systemic bias against women. All of the most senior positions in the central bank are filled by men.

EU leaders can still appoint Mersch over and above the European Parliament's objections, but the parliament's move makes it politically more difficult for that to happen.

The ECB said that Mersch's candidacy was safe.

"In our case, especially in times of crisis, the Executive Board (of the ECB) should be completed and this nomination should go through," Mario Draghi the head of the ECB said on Tuesday.

Mersch's spokesperson declined to comment.

In the 14 years since the ECB was founded as guardian of the euro single currency, two women have sat on the six-member executive board, Finland's Sirkka Hämäläinen and Austria's Gertrude Tumpel-Gugerell.

Euro zone finance ministers nominated Mersch, the governor of the central bank of Luxembourg, to the executive board in July 2012, replacing Spain's José Manuel González Páramo, whose term expired at the end of May.

The Executive Board will not have another position open until June 2018.

(Reporting By Claire Davenport; additional reporting Sakari Suoninen and Eva Kuehnen; editing by Luke Baker)