ASHINGTON, June 25 ? The State Department's intelligence division is disputing the Central Intelligence Agency's conclusion that mysterious trailers found in Iraq were for making biological weapons, United States government officials said today.

In a classified June 2 memorandum, the officials said, the department's Bureau of Intelligence and Research said it was premature to conclude that the trailers were evidence of an Iraqi biological weapons program, as President Bush has done. The disclosure of the memorandum is the clearest sign yet of disagreement between intelligence agencies over the assertion, which was produced jointly by the C.I.A. and the Defense Intelligence Agency and made public on May 28 on the C.I.A. Web site. Officials said the C.I.A. and D.I.A. did not consult with other intelligence agencies before issuing the report.