Japan is set to take part in joint naval exercises with India and the United States in the Indian Ocean in October, military and diplomatic sources said, a drill that so riled China eight years ago that Delhi has not since hosted such a multilateral exercise.

The Indian Ocean has emerged as a new arena of competition between China making inroads and India trying to recover its position as the dominant maritime power in the region.

New Delhi's decision to expand the "Malabar" exercises that it conducts with the United States each year to include Japan suggests a tightening of military relations between three major maritime powers in Asia, analysts said.