Fewer than a third of the UK companies questioned in the latest Barclaycard Business Travel Survey use a travel agent for their travel bookings.
The number using an agency dropped slightly form 2003 to 2004 as more companies and individuals turned to online booking.
The research which questioned 1,200 executives including ceos, found that 77% had booked flights on online, a rise of 11% on 2003, 73% hotels and 34% train trips.
Nearly two thirds of those booking on the web (64%) cited convenience as their main reason but 16% said it helped manage travel costs and 11% highlighted its reliability.
UK companies now expected nearly a third of their travellers to book their travel online in 2004 compared with 2% for 2003.
Mr Tim Carlier, Barclay's head of issuing, said the findings were a strong challenge to the business travel agencies.
“Companies appear to be introducing ever more efficient travel booking procedures. An increasing number of companies insist employees purchase travel online in order to be cost effective,” he said.
“Booking on the internet often has good management information detailing all areas of spend and can provide cheaper alternatives at the click of a mouse.
“However, business travel agencies (BTAs) provide added value to customers and there are clear advantages of having a travel expert rather than a computer serving customers' travel needs.
“The leisure, catering and health industries are least likely to use BTAs at present, according to the survey, and are potential areas where BTAs could win additional business.”