Foreign Investment Promotion Board (FIPB) approved Telephonics Corporation's equity stake hike in Mahindra Telephonics Integrated Systems (MTIS) from 26% to 49% on Aug. 14, 2015.

Telephonics Corporation is a subsidiary company of Griffon Corporation, a diversified manufacturing firm.

Mahindra group and Telephonics Corporation formed their joint venture (JV), MTIS in March 2013. As per the agreement, Mahindra Defence Systems held 74% stake in the JV, with Telephonics taking the remaining 26%.

Shares of the company declined Rs 32.15, or 2.81%, to trade at Rs 1,112.20. The total volume of shares traded was 663,716 at the BSE (4.00 p.m., Friday).