Vietcombank sold the greenback at VND26,305, down 0.09% from Monday.
The State Bank of Vietnam lowered its reference rate by 0.03% to VND25,121.
The dollar was steady on the black market at VND26,500.
Globally the dollar rose 0.2% to 146.36 yen, touching a two-week high. The euro was flat at $1.1741, Reuters reported.
The Aussie advanced 0.4% to $0.6516 before a meeting by the central bank where policymakers are widely expected to deliver a 25-basis-point cut.