The buyers were state-owned gold producer and distributor Saigon Jewelry Company and lender ACB, a source told VnExpress.
They bought a total of 3,400 taels out of the 16,800 that the central bank offered for sale. A tael equals 37.5 grams or 1.2 ounces.
The transaction prices were slightly above the minimum set at the auction, with the gold being bought for VND81.33 million and VND81.32 million per tael, against a base price of VND81.30 million.
Six other banks and three other gold distributors participated in the auction but did not make bids.
They are VPBank, HDBank, Techcombank, Eximbank, MSB, Sacombank, DOJI, Phu Nhuan Jewelry and Phu Quy.
Huynh Trung Khanh, deputy chairman of the Vietnam Gold Traders Association, said that gold bar buyers will sell directly to consumers and will sell in bulk to other businesses.
Few banks sell gold and therefore they are not likely to make bids, he added.
On the market gold bar price fell 1.13% to VND82.5 million per tael as of 4:09 p.m.