Vietcombank sold the greenback at VND26,457, down 0.04% from Tuesday. The currency traded at around VND26,535 on the black market.
The State Bank of Vietnam lowered its rate by 0.04% to VND25,198.
Globally, the U.S. dollar loitered near four-year lows against the euro and a one-month trough against the yen on Wednesday, as traders geared up for a near-certain interest rate cut from the Federal Reserve later in the session, Reuters reported.
The euro wobbled at $1.1858, just below the four-year high of $1.18785 it touched on Tuesday. Sterling was steady at $1.3649, hovering near 2-1/2-month highs.
The dollar index, which measures the U.S. unit against six others, was at 96.686, languishing near its lowest since early July.
The Japanese yen firmed to 146.22 per dollar, its strongest in a month ahead of the Bank of Japan policy meeting on Friday where the central bank is expected to stand pat on rates.