—Order and amended judgment (one paper), Supreme Court, New York County (Salvador Collazo, J.), entered June 14, 1994, brought up for review pursuant to CPLR 5517 (b) on cross appeals from order and judgment (one paper) of the same court and Justice entered October 20, 1993, which, after a nonjury trial, awarded plaintiff the sum of $468,805.62, unanimously modified, on the law, to the extent of remanding the matter for a determination of pre-decision interest, and otherwise affirmed, without costs.
Determination of the credibility of witnesses, as well as the weight to be accorded to the evidence, are primarily questions to be determined by the trier of fact and should not be disturbed when supported by a fair interpretation of the evidence (Matter of Kaplan v Werlin, 215 AD2d 387). The record supports the trial court’s determination that plaintiff earned fees in connection with its five year representation of defendant, based on the unambiguous, fair and reasonable retainer agreement which was fully understood by the client (Shaw v Manufacturers Hanover Trust Co., 68 NY2d 172, 176) and on the subsequent memoranda incorporating the parties’ oral agreements. Plaintiff further demonstrated its entitlement to the quantum meruit award, as granted by the trial court, for other services not covered by the parties’ express agreements (see, Bradkin v Leverton, 26 NY2d 192).
Plaintiff is also entitled to pre-judgment interest (CPLR 5001; Kleartone Transparent Prods. Co. v Dun & Bradstreet, 118 AD2d 832).
We have considered defendant’s remaining contentions and find them to be without merit. Concur — Milonas, J. P., Rosenberger, Rubin, Kupferman and Mazzarelli, JJ.