India's MTNL shares rise 4% as DoT urges state-owned telecom to use for security, potentially impacting private providers' revenue.

• MTNL up 4% on report of security, driven state telecom preference directive.
• Private ISPs could lose thousands of crores annually if the policy is implemented.
• Bharti Airtel, Vodafone Idea, and Reliance Jio shares decline slightly.