[GRAPHIC OMITTED] PPG Industries PPG Industries, Inc. One PPG Place Pittsburgh, Pennsylvania 15272 USA Telephone (412) 434-2342 Fax (412) 434-3700 fheinemann@ppg.com Frank W. Heinemann Director Manufacturing & Applied Technology, Optical Products April 11, 2003 Ms. Janice K. Mahon Vice President of Technology Commercialization Universal Display Corporation 375 Phillips Boulevard Ewing, NJ 08618 RE: UDC - PPG Development and License Agreement (October 1, 2000) - Third Amendment Dear Janice: At the request of Universal Display Corporation (UDC), PPG is willing to add [The confidential material contained herein has been omitted and has been separately filed with the Commission.] additional [The confidential material contained herein has been omitted and has been separately filed with the Commission.] materials [The confidential material contained herein has been omitted and has been separately filed with the Commission.] to the list of [The confidential material contained herein has been omitted and has been separately filed with the Commission.] Chemicals manufactured by PPG and supplied to UDC under the above subject Agreement. Attachment A is hereby amended to include the listing of these materials (copy attached). Upon acceptance by UDC, please sign both originals retaining one for your files and returning the other to my attention. Best regards, Frank W. Heinemann - -------------------------------------------- Frank W. Heinemann ACKNOWLEDGED AND AGREED TO: Universal Display Corporation. By: Janice K. Mahon -------------------------------------- Print Name: Janice K. Mahon ------------------------------- Title: V.P. of Technology Commercialization ATTACHMENT A [The confidential material contained herein has been omitted and has been separately filed with the Commission.]