DECISION ORDER
ORDERED that the judgment is affirmed insofar as appealed from, with one bill of costs.
Contrary to the plaintiffs' contention, the Trial Judge did not improvidently exercise his discretion in permitting the defendants' expert witness to testify. The plaintiffs presented no evidence suggesting that the defendants intentionally or willfully withheld notice that the expert would testify, and did not demonstrate any prejudice resulting from the expert witness's testimony (see, Gallo v. Linkow, 255 A.D.2d 113 ; Stafford v. Molinoff, 228 A.D.2d 662 ; Hansel v. Lamb, 257 A.D.2d 795 ).
In addition, the Trial Judge did not unduly interfere with the presentation of the plaintiffs' case or indicate any partiality or bias which would warrant reversal. A Trial Judge may assume an active role in the examination of witnesses where proper or necessary to facilitate or expedite the orderly progress of the trial (see, Givens v. Sinert, 243 A.D.2d 443 ; Accardi v. City of New York, 121 A.D.2d 489, 491 ).
The plaintiffs' remaining contentions do not require reversal.
SULLIVAN, J.P., FRIEDMANN, FEUERSTEIN, and SMITH, JJ., concur.