The two have seen a declinein sales of 5 percent and 17 percent respectively since 2012, said thereport which was released on May 27, adding that the frequency of visitsalso decreased.
While consumers have become more "savvy" intheir shopping behaviour in recent years, the need for conveniencecontinues to grow.
In Vietnam, store expansion also continues to gain momentum, especially in urban areas.
Convenience stores more than doubled from 147 in 2012 to 348 last year, while mini marts increased from 863 to 1452.
Thisnew demand is being led by time-poor and predominantly young shoppersin making everyday food and grocery purchases, and has been a key driverin convenience store expansion.
Some 22 percent of consumers shop for food and grocery more often at convenience stores compared to 12 months ago.
Foodand beverages are driving convenience store sales, with 86 percent ofconsumers buying either and 62 percent of beverage buyers also buyingfood and 51 percent of food buyers also buying beverages.
VaughanRyan, Managing Director of Nielsen Vietnam, said: "Convenience is not astore front, but rather a way of life. Consumers are increasinglydemanding products and solutions that help them in their increasinglybusy life.
"As a result we will see the emergence in Vietnam of both the convenience channel and e-commerce to meet this consumer demand."
Toaddress these shifts, retailers must deepen their understanding of thisevolving shopper behaviour, foresee changing needs and developstrategies that are focused on differentiation in areas that matter mostto shoppers, he added.-VNA