The current account deficit for the same period in 2008 was equivalent to 2.2% GDP.
The deficit was US$3.46 billion in the first nine months of 2009, compared with a revised deficit of US$4.19 billion in the same period a year earlier.
The fall in the deficit is due to foreign companies transferring less of the profits from their Colombian operations back to their home countries.
Foreign companies, mainly coal and nickel miners and oil producers, repatriated US$6.7 billion in the first nine months, down from US$7.96 billion in the same period in 2008.
Additionally, the country registered a smaller trade surplus of US$1.65 billion, compared with US$1.86 billion in the same period in 2008, as revenue from commodities such as oil, coal and nickel fell because of lower prices.
Remittances from Colombians living abroad fell 17% to US$3.02 billion from US$3.65 billion.
Net foreign direct investment fell in the first nine months of 2009 to US$6.45 billion from US$8 billion in the year-earlier period.
The bank attributed part of the decline to the US$850 million operation of a foreign company that transferred the ownership of some assets from the parent company to a local subsidiary which accounted as a negative investment.