MISSOULA (AP) — A federal judge has denied a half-dozen motions to dismiss charges against W.R. Grace and Co., including a motion that would have cleared all seven defendants of conspiracy charges.

The conspiracy charges are in a federal indictment alleging Grace endangered residents of Libby and avoided liability by defrauding the government.

Defense attorneys argued that a single count of an indictment cannot charge a defendant with more than one crime. The count alleging conspiracy ‘‘contains allegations of one conspiracy ending in 1995 and a second conspiracy to conceal beginning in 1999,’’ the defense said.

Chief U.S. District Judge Donald Molloy sided with Assistant U.S. Attorney Kris McLean in denying the motion. Molloy wrote that the conspiracy count ‘‘can be fairly read to charge a single offense.’’

At the request of the prosecution, he dismissed two counts of wire fraud against the company.

Molloy granted the prosecution’s motion without prejudice, meaning prosecutors could choose to bring new wire fraud charges later, after a presentation of the entire case to a new grand jury.

The defense argued that prosecutors filed the motion to dismiss the counts alleging wire fraud ‘‘in a strategic effort’’ to give themselves more time, and the defense less time, to respond to charges they will face at trial.

‘‘The defendants’ arguments for dismissal with prejudice are weak,’’ Molloy wrote. ‘‘There is no evidence of improper motive or bad faith on the part of the government, and no apparent strategic benefit to the government in dismissing the wire fraud charges at this point.’’

Last year, a federal grand jury charged that Grace and some top managers conspired to conceal health risks posed by asbestos at the company’s vermiculite mine near Libby, and knowingly endangered members of the community.

Seven of the company’s current and former officers are scheduled for trial Sept. 11 in Missoula.