In a letter to the Israeli Prime Minister Benjamin Netanyahu, Singh said that Sharon made extremely important contributions to Israel and took bold steps for bringing peace in the region.
"I was deeply saddened to learn of the demise of Ariel Sharon. During his long career in public service, Sharon made extremely important contributions to the State of Israel. In this hour of bereavement, please accept our heartfelt condolences and sympathies," he said.
Sharon, a hardliner revered by his countrymen as "Mr Security" and reviled across the Arab world as the "butcher of Sabra and Shatila", died on January 11 at the age of 85 after being comatose for eight years.
Recalling Sharon's visit to India in September 2003, Singh said that he was the first Prime Minister of Israel to visit India.
"As Prime Minister, he took bold steps for peace in the region. We in India recall that he was the first-ever Prime Minister of Israel to visit India in September 2003. His lasting contribution to the promotion of our bilateral ties will be long remembered," Singh said.
Sharon was elected prime minister in 2001 and served until he suffered a massive stroke that left him comatose on January 4, 2006. His condition deteriorated on New Year's day, when he suffered serious kidney problems after surgery.