BERLIN (Reuters) - The chief of stricken German state bank KfW [KFW.UL] said on Monday she would resign, as the bill to save KfW-controlled subprime casualty IKB (IKBG.DE: Quote, Profile, Research) mounted.

KfW said current board member Wolfgang Kroh will provisionally head KfW, taking over from Ingrid Matthaeus-Maier, who stepped down after facing criticism over the handling of the crisis at IKB.

KfW has taken a 1.8 billion euro ($2.83 billion) hit from liquidity lines given to IKB, KfW chairman Michael Glos said.

The finance expert of the conservative CDU/CSU parliamentary group, Otto Bernhard, suggested in an interview to be published on Tuesday in the Financial Times Deutschland that Bundesbank executive board member Hans Reckers -- widely considered to be a leading candidate -- could take over at KfW.

At an event on Monday evening, German Finance Minister Peer Steinbrueck of the SPD party said the new KfW chief would have to be an experienced banker and not a political nominee -- a veiled reference to party colleague Matthaeus-Maier, who was a career politician before she joined the KfW management board in 1999.

Glos, who is also economy minister, said KfW's supervisory board had approved the bank's annual report for 2007. The bank showed a loss of 6.2 billion euros, he said.

Without the burden of write-downs and the IKB, the major shareholder of which is KfW, the state bank would have had a profit of some 1 billion euros, Glos added.

IKB is Germany's highest-profile casualty of the global financial markets crisis. It has been rescued three times at a cost of more than 8 billion euros ($12.58 billion), mostly with the help of government-owned KfW.

IKB, once a little-known lender to small German companies, shot to fame last year as Germany's first casualty of the subprime mortgage crisis in the United States, when billions of euros (dollars) of its investments turned sour.