KARACHI (Reuters) - Tributes for Pakistan's late former military spy chief Lieutenant General Hamid Gul poured in on Sunday, words bound to infuriate Pakistan's neighbors after he spent a career promoting Islamic militancy in Afghanistan and India.

"(Prime Minister) Nawaz Sharif has expressed his heartfelt condolences over the sad demise of ... Hamid Gul," the ruling party's media office said on Twitter. "The prime minister prayed eternal peace for the departed soul and said that may God bless the deceased."

Legislator Arif Alvi tweeted that Gul had died on Saturday night of a brain hemorrhage at age 79 and called him "a great man".

The tributes will anger Afghanistan and India, who saw Gul as Pakistan's most senior and vocal proponent of militancy in their territory.

Gul worked closely with U.S. and Saudi officials to strengthen Afghan fighters against the Soviet military when he headed the feared military intelligence agency, the Inter-Services Intelligence, from 1987 to 1989. Some of those fighters later joined the Taliban insurgency.

Towards the end of his posting, officials began diverting men and guns from the Afghan war towards budding militant groups like Lashkar-e-Taiba, founded in 1990 as a separatist movement in Indian Kashmir.

The disputed Himalayan region is claimed by both India and Pakistan and has sparked two of the three wars fought between the nuclear-armed neighbors since they began separate nations in 1947.

After Gul retired, he frequently went on television to defend the Taliban and Kashmiri militants and blame a Jewish conspiracy for the September 11, 2001, attacks on the United States.

(Editing by Nick Macfie)