Panicker (78) is survived by his wife DS Panickerr, RSS sources said.
Panicker had started his career as a steno-typist in RSP before joining trade union and subsequent formation of RSS which became a formidable force in the steel plant.
He had successfully fought the case in Supreme Court against RSP management which helped over 4500 contract labourers getting regularised in the central PSU.
Because of his huge support base, which almost remained intact till date, he enjoyed clout over the politics in the steel city.