Bad debts in Vietnamese banks accounted for 4.64 percent of total loans at the end of August, up from 4.58 percent the previous month, the central bank said on Monday.
Banks reported total loans of 3,290 trillion dong ($156 billion) at the end of August, up 6.44 percent from the end of 2012, the State Bank of Vietnam said in a report on its website, suggesting bad debts would stand at $7.24 billion.
Independent experts have estimated that bad debts at Vietnam's banks could be considerably higher than reported.
State-owned banks are saddled with huge debts to state firms and have been blamed for high rates of real estate-related bad debts.
Vietnam's economy, which slowed in 2012 as banks tightened lending to avoid bad debts, has been accelerating so far this year, but fresh funds remain limited as banks have yet to complete cleaning their books.
To deal with the bad debt situation, the central bank in July launched an asset firm to buy them from banks, a move touted as one of its biggest reforms but widely seen as a band-aid fix for its ailing, credit-starved economy.
Banks may achieve annual credit growth of between 11 and 12 percent this year, in line with the central bank's target of 12 percent, State Bank of Vietnam Governor Nguyen Van Binh told parliament in late October.
The country's credit growth at the end of October quickened to 7.89 percent from the end of 2012, Binh was quoted by the Securities Investment magazine as saying in parliament, reflecting banks' faster lending in the past month.