I would affirm. A stipulation of settlement which meets the open court requirements of CPLR 2104 cannot be set aside except for reasons that would invalidate a contract (see Yonkers Fur Dressing Co. v Royal Ins. Co., 247 NY 435, 446). Here, the ground advanced for setting aside the stipulation, plaintiffs’ claimed mistake, is not even remotely borne out by the evidence. Plaintiff Phillips, who was not only present in chambers when the settlement was entered into but also had his personal attorney by his side, never uttered a word of discontent with, nor had his personal attorney register any objection to, the terms of the settlement arrived at by defendant Quartararo, the trial counsel. Given these circumstances, Phillips is foreclosed from challenging the settlement. Plaintiff Hallock also cloaked attorney Quartararo with apparent, if not real, authority to settle and, therefore, he too should be barred. Quartararo had represented these plaintiffs for five years throughout the entire action; he had conducted examinations before trial, negotiated with the State on plaintiffs’ behalf and prepared for trial. Although plaintiffs maintain he exceeded his settlement authority with regard to the particular terms of the final settlement, it is uncontroverted that he did indeed have authority to negotiate on their behalf. These established facts, considered in conjunction with the principle that an attorney participating in a pretrial conference must have authority to negotiate binding settlements and his appearance constitutes apparent and implied authority to obligate his client unless expressly qualified (Di Russo v Grant, 28 AD2d 847), requires a finding that this settlement was conclusive on the parties. To decide otherwise invites destruction of the process of open-court settlements, for every such settlement would be liable to subsequent rescission by the simple expedient of a litigant’s self-serving assertion, joined in by his attorney and previously uncommunicated to either the court or others involved in the settlement, that the litigant *859had limited his attorney’s authority. The possibilities for abuse which this practice would lend itself to are self-evident. While the trial court’s refusal to allow plaintiff Phillips to read clarifying portions of his examination before trial was error, in my view it was harmless, for as already noted Phillips was bound by Quartararc’s actions. As for plaintiff Hallock, the court’s refusal to allow clarifying passages to be read from his deposition was also harmless error, but for a different reason. In the three instances defendants used Hallock’s deposition to impeach, the issues raised were collateral to the question of his attorney’s authority to settle on his behalf. Moreover, the trial court’s finding that it lacked confidence in the credibility of Hallock’s testimony went beyond inconsistencies between his deposition and trial testimony; it was based on Hallock’s failure to recall many events and communications as well as inconsistencies which permeated his in-court testimony. Furthermore, in arriving at that conclusion the trial court had what we lack, the invaluable advantage of observing the witness testify. Accordingly, I would affirm the judgment entered below.