FamilyMart Co. plans to open 600 stores in Indonesia and the Philippines, tapping demand from young people as an aging population saps growth at home.

FamilyMart, Japan's largest convenience store chain in Southeast Asia, intends to have 300 stores in each country by 2015, Masaaki Kosaka, director of overseas operations, said in a Jan. 13 interview in Tokyo. He declined to say how much the expansion would cost.

FamilyMart joins larger Japanese competitors Lawson Inc. and Seven & I Holdings Co. in planning to open more stores in faster-growing Asian markets. The International Monetary Fund has forecast 5.6 percent economic growth this year in Southeast Asia, double its projection of 2.3 percent in Japan, as relatively young populations drive consumption.