The move came as prosecutors cited doubts over the credibility of his accuser, 32-year-old hotel maid Nafissatou Diallo.
The dismissal of criminal charges at the New York State Supreme Court will take effect once the judge rules on an appeal against the move.
Mr Strauss-Kahn, 62, was accused in May of attacking the African immigrant as she entered his hotel room to clean it.
The ruling means he is a free man, though he still faces a civil suit Ms Diallo filed this month. "Our inability to believe the complainant beyond a reasonable doubt means, in good faith, that we could not ask a jury to do that," Assistant District Attorney Joan Illuzzi-Orbon told Judge Michael Obus.
Mr Strauss-Kahn, considered a French presidential contender before the case, arrived for the hearing in lower Manhattan on Tuesday in a six-car motorcade with his wife Anne Sinclair.
Add new comment