The Office of National Statistics surveyed 9,000 UK businesses with 10 or more employees about their use of, and attitude towards, the Internet and e-commerce.
The E-Commerce Inquiry, which defines an e-commerce transaction as the method by which an order is placed, rather than the payment method or the delivery channel, is the first national research of its kind. It will be published annually.
Sales conducted over all electronic channels in 2000, including the Internet and other "computer-mediated" networks such as electronic data interchange, reached £161.75bn, or nearly 6% of total sales.
The financial and insurance sector took the lion's share of Internet sales, conducting an estimated £44bn worth of online business. This figure rose to nearly £80bn when sales over all other electronic channels were included.
The wholesale, retail and travel sectors sold £7.6bn worth of goods online.
Although the majority of sales were business-to-business transactions, only 16% of companies admitted to using the Internet or other computer networks to make sales. Another 12% said they intended to move into online sales within a year, but 70% said they had no plans to sell through electronic channels within the coming year.
Business-to-consumer transactions accounted for less than 20% (about £10bn) of total sales, the vast majority of which were in the financial sector.