Ordered that the order is affirmed, with costs.
The amended provisions of CPLR 3101 (d) in effect at the time of this appeal are applicable only to actions commenced on or after July 1, 1985 (see, CPLR 3101 [d], as amended by L 1985, ch 294; see also, McKinstry v Werner Mach. Co., 133 A.D.2d 361; Humiston v Rochester Inst. of Technology, 125 A.D.2d 957). The instant action was commenced prior to that date and is thus subject to the earlier rule which generally prohibited discovery of experts' reports unless such material could not be duplicated by reason of a change in conditions and withholding such information would result in injustice or undue hardship. By parity of reasoning, one party could not generally call the other party's expert as a witness at an examination before trial because of the risk that material protected by CPLR 3101 (former [d]) would be discovered (see, Coley v Michelin Tire Corp., 75 A.D.2d 610). The defendant has failed to demonstrate the existence of circumstances sufficient under CPLR 3101 (former [d]) to warrant disclosure of any reports prepared by experts on behalf of the plaintiff or the third-party defendant or to compel a deposition of such experts. The order under review is accordingly affirmed. Thompson, J.P., Lawrence, Rubin, Harwood and Balletta, JJ., concur.