Order unanimously reversed, with costs, and motion denied without prejudice to renew within 20 days from the date of service of the order herein. Memorandum: Third-party defendant's motion for a protective order denying discovery of the results of certain tests was improperly granted (CPLR 3103). A party opposing discovery bears the burden of proving that the material sought was prepared for litigation and, therefore, was immune from disclosure pursuant to CPLR 3101 (subd [d]) (Koump v Smith, 25 N.Y.2d 287, 294; Mobil Oil Corp. v State of New York, 52 A.D.2d 1033). The attorney's conclusory allegations were insufficient to meet this burden (Hunt v Joseph, 67 A.D.2d 697).