Army Col. Denise Lind denied the defence motion during a pretrial hearing at Fort Meade in the court-martial of Pfc. Bradley Manning. The ruling means the hearing will continue. It's scheduled to run through Thursday.
The defence has filed a separate motion seeking dismissal of the most serious charge, aiding the enemy. That offence carries a maximum penalty of life imprisonment.
Lind tentatively scheduled the trial to run from Sept. 21 through Oct. 12.
Manning is accused of sending hundreds of thousands of sensitive documents to the anti-secrecy website WikiLeaks.
In seeking the dismissal, Manning's lawyers had argued that prosecutors were so slow in sharing required information with the defence that the only remedy was to throw out the charges.
Prosecutors said they worked diligently to meet their obligations. They maintained that they needed time to obtain documents from civilian agencies and search the records for relevant material.
The 24-year-old Oklahoma native was ordered court-martialed after he was accused of downloading the documents, diplomatic cables and video clips, then sending them to WikiLeaks. He was working as an intelligence analyst in Baghdad when authorities say he copied classified material from government computers in late 2009 and early 2010.
The material WikiLeaks published included cockpit video of a 2007 U.S. Apache helicopter attack that killed a number of civilians, including a Reuters news photographer and his driver. The U.S. government says the civilian deaths were accidental.
Manning has been in pretrial confinement since he was charged in May 2010. His treatment at a Marine Corps base caused support for him to swell. The Quantico, Va., brig commander kept Manning confined 23 hours a day in a single-bed cell, citing safety and security concerns. For several days in March 2011, he was forced to sleep naked, purportedly for injury prevention, before he was issued a suicide-prevention smock.