Mr. Ray, whose office has investigated President and Mrs. Clinton for more than four years, also said in an interview that he would announce his decision shortly after the president left office on whether he would seek to indict Mr. Clinton in connection with his affair with a White House intern.
Mr. Ray has already issued two reports, one essentially clearing the Clintons in the collection of confidential FBI files about Republicans, and another critical of Mrs. Clinton's role in the dismissal of longtime employees in the White House travel office.
Any criticism of Mrs. Clinton from Mr. Ray in the final weeks of her campaign could turn into a political issue.
But Howard Wolfson, Mrs. Clinton's campaign spokesman, said Monday in response to Mr. Ray's plans: "New Yorkers have already made up their minds about this. They know there is nothing here."
Mr. Ray refused to discuss what the Whitewater report might contain. While it has long been known there will be no recommendation of any criminal indictment, the statement is almost certain to discuss how his findings compare with Mrs. Clinton's assertions to investigators and to the public about her role as a lawyer in connection with several real estate dealings in Arkansas.
"It's my intention to issue those findings and conclusions prior to the election," he said. "Right now I'm trying for mid-September."
He said it would be wrong to delay disclosing his findings.
Mr. Ray said issuing his statement a few weeks before the election would provide enough time for anyone to respond to it and for the public to fully absorb his views and those of anyone who disputed his findings.
With regard to his decision about the president, Mr. Ray said he had an obligation to conclude the matter as soon as possible.
"It's time this matter was brought to closure ," he said. "And it is coming to closure."