CORNING <GLW>, HAZLETON <HLC> SET EXCAHNGE RATIO Corning Glass Works said the exchange ratio for its previously announced acquisition of Hazleton Laboratories Corp has been established at 0.5165 Corning common share for each Hazleton common share. Corning said the prospectus regarding the merger is expected to be mailed tomorrow to all Hazleton holders of record February 18. Hazleton shareholders will vote on the proposed merger at a special meeting on March 31.