** Shares of specialty glass maker Corning GLW.N down ~12% at $148.01 premarket
** GLW, a key supplier to Apple AAPL.O, forecasts Q2 core sales of about $4.6 bln, vs analysts' estimate of $4.63 bln - data compiled by LSEG
** Posts Q1 core sales of $4.35 bln vs estimate of $4.26 bln, while adj. EPS at 70 cents is above the estimate of 69 cents
** Corning says it has signed long-term agreements with two hyperscalers
** GLW stock up 91.8% YTD
(Reporting by Tharuniyaa Lakshmi in Bengaluru)
((tharuniyaa@thomsonreuters.com))