The agency says wholesale trade, manufacturing and retail trade accounted for 61% of the value of ecommerce sales, similar to the 2012 results.
It says about 13% of businesses sold goods or services over the internet in 2013, up from 11% in 2012.
Large companies, those with 100 or more employees, accounted for nearly all of the growth in the value of online sales in 2013.
These businesses were responsible for about $87 billion, or 64% of the value of total online sales.
For businesses that sold online in 2013, almost a quarter of the value of their total sales came from internet transactions.