X0303 4 2010-01-06 0001005284 UNIVERSAL DISPLAY CORP \PA\ PANL 0001423446 Mahon Janice K 375 PHILLIPS BLVD. EWING NJ 08618 0 1 0 0 VP of Tech Commercialization Common Stock 2010-01-06 4 A 0 5398 0 A 25148 D Common Stock 2010-01-06 4 F 0 2290 14.17 D 22858 D Common Stock 2010-01-06 4 A 0 4446 0 A 27304 D Common Stock 2010-01-06 4 F 0 824 14.17 D 26480 D These shares were withheld to satisfy a tax liability. These shares are subject to a vesting restriction, with one-third of the total share amount vesting on each of January 6, 2011, 2012 and 2013. These shares were withheld to satisfy a tax liability in connection with the vesting, on January 6, 2010, of 2,075 shares of restricted stock previously granted to Ms. Mahon. /s/ Steven V. Abramson (by power of attorney) 2010-01-08