A staunch Stalin loyalist, Kalyanasundaram in his July 31 letter, copy of which was released to media by him today, tendered his resignation as Director of Kalaignar TV Private Ltd and also Anjugam Films Pvt Limited.
He sent the letters to V Amirtham, who is also a director in both the companies.
Kalyanasundaram was on August 7 suspended from all party posts, including that of Organising Secretary, and primary membership on the charge of indiscipline, days after he submitted his resignation from the party demanding that Stalin, younger son of DMK chief M Karunanidhi, be declared the chief ministerial candidate.
DMK General Secretary K Anbazhagan had announced the suspension saying Kalyanasundaram was working against party's interest and thus bringing disrepute.
Kalyanasundaram had also suggested that Karunanidhi's daughter Kanimozhi and former Union ministers A Raja and Dayanidhi Maran remain "aloof" from the party and urged the leadership to remove from party posts, functionaries "facing land-grabbing and disproportionate assets cases".
Stalin's supporters have been pressing for his elevation for long, but Karunanidhi has deferred a decision amid sibling rivalry involving his Madurai-based elder son M K Alagiri, who had been expelled from DMK recently, and Stalin over the succession issue.