MTNL Mahanagar Telephone Nigam Ltd Other Situations Announcement 2026 - Trading Window Closure MTNL to close trading window from 1 April 2026 until 48 hours after FY2025-26 results, restricting insiders from trading MTNL securities..Find Corporate Announcements for Press Releases, AGM, Insider Trading & SAST, Results and Corporate Action for Mahanagar Telephone Nigam Ltd