NEW YORK - Dominique Strauss-Kahn, head of the IMF, is under growing pressure to resign since his bail was denied on Monday and a trial will not begin until six months later, which could severely impair his ability to run the Fund.

The IMF said it had not been in touch with Strauss-Kahn since his arrest but it would be important to do so "in due course" and ask whether he planned to continue in his post.

In the United States, the IMF's biggest shareholder, politicians began questioning the viability of his tenure as head of the institution charged with managing the world economy and central to negotiating debt crisis deals.

"I can't comment on the case, but he is obviously not in a position to run the IMF," US Treasury Secretary Timothy Geithner said.

John Lipsky, the second-in-command, is in charge during Strauss-Kahn's absence, but no formal interim chief has been named. IMF sources said that David Lipton, White House international economic adviser and former deputy treasury secretary, would take Lipsky's deputy position.

In Europe, Strauss-Kahn was also losing support though the IMF is helping eurozone states like Greece and Portugal tackle debt woes.

"Given the situation, that bail has been denied, he has to consider that he would otherwise do damage to the institution," said Austrian Finance Minister Maria Fekter.

Spanish Economy Minister Elena Salgado cast doubt on Strauss-Kahn's judgment but said it was his decision whether to resign.

"That is a decision which is up to Mr Strauss-Kahn to take, but the crimes he is accused of are very serious ... My solidarity first and foremost is with the woman who suffered the attack, if that was what happened," she told reporters.

But in France, President Nicolas Sarkozy urged center-right lawmakers at a closed-door breakfast to show "restraint and dignity" and refrain from comment on the Strauss-Kahn case, participants said.

And the Socialist Party's leadership staged a rare show of unity amid consternation over the probable loss of the center-left's most popular contender to unseat conservative President Nicolas Sarkozy in next April's election.

Many of them voiced outrage at the way the US police walked Strauss-Kahn briefly in front of a battery of cameras on Sunday night. The front-runner for the French presidency had been handcuffed and unshaven before he has had a chance to defend himself in court.

AFP-Reuters