Vietnam's benchmark VN Index ended down 0.21 percent on Friday for a straight second session of losses with most bluechips heading south led by food stocks. Dairy products maker Vinamilk, the country's top firm by market value, eased 0.69 percent, followed by food producer Masan Group, which dropped 2.08 percent. The index, Southeast Asia's best performer in 2015, has gained a combined 0.7 percent, posting the sixth straight weekly gain, Reuters data showed.