Mahila Court Judge Meena Sathish held Moorthy guilty of killing his wife in Karnakinagar area of Chennai and pronounced the verdict on him, the prosecution sources said.
The court also imposed a fine of Rs 10,000 on the convict, they added.
Moorthy and Sumathy, who had two sons and a daughter, had parted ways following differences of opinion and were living separately.
The incident took place on January 14, 2012 when the convict attacked his wife with an iron rod in a flower shop where she used to work. She died on the spot.