Roy Lee, Sterling's vice-president of marketing for Europe, Middle East and Africa, said many companies were looking to combine the two protocols, including UK supermarket chain Asda, French supermarket chain Auchan and catering group Compass.

They are using Sterling Integrator, its combined EDI and AS2 offering, recently introduced into Europe.

"We believe this hybrid model of EDI and AS2 will be the one that wins out," he said.

Many smaller suppliers still find EDI expensive because it relies on proprietary networks.

Users can transfer EDI documents securely over the Internet with AS2, which is also cheap to set up because it uses an existing network. "But AS2 alone can't tell you when data has or hasn't arrived," Lee said.

Sterling Integrator offers the "value-added network" EDI for sending critical data, while AS2 can be used for less business critical information, he added.

Suppliers can also use the AS2 part of the system to communicate with each other.